Acronyms and Glossary of Terms

Acronyms and Glossary of Terms

Abacus is an adaptation of the traditional Japanese abacus used to teach basic number concepts, addition and subtraction for students with visual impairments. 

Academy for Certification of Vision Rehabilitation & Education Professionals (ACVREP)

Accessible Educational Materials (AEM): Materials that are designed or converted in a way that makes them usable across the widest range of student variability regardless of format (print, digital, graphical, audio, video). 

Accessible Instructional Materials (AIM): Materials that are designed or modified to provide access to the widest possible range of students, including those with disabilities. Accessible formats may include Braille, large print, audio, or digital materials. AIM is required under Individuals with Disabilities Education Act for students who cannot access or use traditional print materials. 

Active Middle Ear Implants (AMEI) consist of an external audio processor and an internal implant, which actively vibrates the structures of the middle ear.

Activities for Daily Living (ADL) are the tasks a sighted person takes for granted such as doing the laundry or dishes, selecting an outfit, compliantly taking medicine, preparing a meal, etc.

Acuity is measure of the ability to see details of the smallest possible letter or symbol. Typical acuity is 20/20 (print size/distance). 

Adaptive Paper provides extra visual or tactile cues and feedback to aid in the process of writing. Examples include raised-line paper, dark-line paper, color-coded paper, and writing guides. 

Adventitious Blindness refers to loss of vision acquired after birth (or after 5 years or so) as a result of illness or accident

All India Flag Day for the Blind: [India] Every 14th September, Finance Raising Committee (FRC) of NAB India organizes the All India Flag Day for the Blind. To mark the occasion, it calls on important personalities in Mumbai – the Governor, the Mayor, the chiefs of Indian Army and Navy bases in the city, heads of public and private sector establishments etc. It becomes a day of celebration and expression of talent and joy. Performances become a way to reach to people’s heart and start a new way of looking at world

American Printing House (APH) provides accessible learning materials such as large print and braille material, braille labelers, braille toys/games, and tactile aids for learning for the Blind.

Antihelix (Anthelix) is a part of the visible ear; the pinna. The antihelix is a curved prominence of cartilage parallel with and in front of the helix on the pinna.

American Sign Language (ASL): American Sign Language (ASL) is a natural language that serves as the predominant sign language of Deaf communities in the United States and most of Anglophone Canada. ASL is a complete and organized visual language that is expressed by both manual and nonmanual features. Besides North America, dialects of ASL and ASL-based creoles are used in many countries around the world, including much of West Africa and parts of Southeast Asia. ASL is most closely related to French Sign Language (LSF). 

Aphakia is the absence of the lens of the eye, due to surgical removal, such as in cataract surgery, a perforating wound or ulcer, or congenital anomaly. It causes a loss of accommodation, high degree of farsightedness (hyperopia), and a deep anterior chamber.

Applied Behavior Analysis (ABA) is a type of therapeutic intervention that can improve social, communication, and learning skills through reinforcement techniques

Assistive Technology (AT): Any tool that is used to improve, increase or maintain functional capabilities of an individual with a disability. Includes a range from simple and inexpensive low tech solutions to complex high tech systems. Also refers to smartphone apps and other technology which assists someone who is PBVI with ADL’s. There are smartphone apps which detect colors & paper currency denominations, provide navigational assistance, provide text magnification, etc. The term does not include a medical device that is surgically implanted, or the replacement of such device.

Astigmatism is a type of refractive error in which the eye does not focus light evenly on the retina, due to a variation in the optical power of the eye for light coming from different directions.

Audio book is a recording of a book, typically using human voice. May be available in various formats, including MP3, .wav, or DAISY. Some audio book players have advanced navigation and search features (generally requires DAISY format).

Audiobook Month: June

Audiologist: An audiologist is a health-care professional specializing in identifying, diagnosing, treating, and monitoring disorders of the auditory and vestibular systems. Audiologists are trained to diagnose, manage and/or treat hearing, tinnitus, or balance problems.

Audiology is a branch of science that studies hearing, balance, and related disorders.

Audiometer: An audiometer is a machine used for evaluating hearing acuity. They usually consist of an embedded hardware unit connected to a pair of headphones and a test subject feedback button, sometimes controlled by a standard PC. Such systems can also be used with bone vibrators, to test conductive hearing mechanisms. Audiometers are standard equipment at ENT (ear, nose, throat) clinics and in audiology centers. 

Audio-Supported Reading (ASR) is a technology-based approach for accessing and working with text presented in either braille or enlarged (magnified) print. This approach allows a user to listen to a spoken version of text while looking at screen-displayed print or touching braille.

Audism is an attitude based on pathological thinking that results in a negative stigma toward anyone who does not hear; like racism or sexism, audism judges, labels, and limits individuals on the basis of whether a person hears and speaks. Audism reflects the medical view of deafness as a disability that must be fixed. Because many Deaf people grew up in hearing families who did not learn to sign, audism may be ingrained. The term audism was coined in 1975 in an unpublished article written by American communication and language researcher Tom L.

Audists belief that the ability to hear makes one superior to those with hearing loss. 

Auditory Brainstem Implants (ABI) is a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf, due to retrocochlear hearing impairment (due to illness or injury damaging the cochlea or auditory nerve, and so precluding the use of a cochlear implant). 


Auditory Fatigue is defined as a temporary loss of hearing after exposure to sound. This results in a temporary shift of the auditory threshold known as a temporary threshold shift (TTS). The damage can become permanent (permanent threshold shift, PTS) if sufficient recovery time is not allowed before continued sound exposure.

Augmentative and Alternative Communication (AAC)


Auricle or Auricula is the visible part of the ear that is outside the head. It is also called the pinna.


Behavior Analyst Certification Board (BACB) is the certifying body that develops and implements the national certification program for behavior analysts.

Behind-The-Ear (BTE) Hearing Aid

Best Corrected Visual Acuity (BCVA): Normal visual acuity is generally accepted as 20/20, although many people can see 20/15, and a few can see 20/10.

Blind/Visually Impaired (B/VI)

Blindness is the inability to see anything using either eye. Blindness and visual impairment are often used somewhat interchangeably as the boundaries aren’t always clear cut. According to the Blindness and Visual Impairment Definitions in India, BCVA/Pinhole <3/60 in better eye with available correction

Blindness Awareness Month: October

Board Certified Assistant Behavior Analyst (BCaBA) is the undergraduate-level certification for BCBAs. BCBAs must be certified by doctoral-level BCBAs (BCBA-D).

Board Certified Behavior Analyst (BCBA) is a person with a certification in applied behavior analysis

Board Certified Behavior Analyst–Doctorate (BCBA-D) is a BCBA who has earned a Ph.D.

Bone-Anchored Hearing Aid (BAHA) is a type of hearing aid based on bone conduction.

Bone Conduction is the conduction of sound to the inner ear primarily through the bones of the skull, allowing the hearer to perceive audio content without blocking the ear canal.

Braille is a tactile reading system, utilizing a 6-dot system of characters, typically used by individuals who have extremely limited or no functional vision. Braille characters represent letters, therefore is an important literacy tool for students who cannot otherwise access text, and should not be substituted entirely by audio. 

Braille and Audio Reading Download (BARD) is a free library service of downloadable braille and audio reading material for residents of the United States and U.S. citizens living abroad who are unable to read or use standard printed material because of visual or physical disabilities. 

Braille Display: See refreshable Braille display.

Braille Embosser is a printer used for producing Braille on paper. 

Braille Notetaker is a portable Braille word processing device with refreshable Braille display and synthesized speech. May have additional features, including personal organization tools, Internet access, e-mail access or GPS. 

Braille Ready Files (BRF) is an electronic text file that is transcribed into braille. You will need specialized software or hardware that can open and read BRF files. Note that most devices will not recognize BRF automatically.

Braille Writer is similar to a typewriter. It uses six keys, that when pressed in various combinations, create Braille code characters on a sheet of paper. Device also has space, backspace and line space keys. May be manual or electronic. 

Canal Receiver Technology (CRT) BTE Hearing Aid. Alternate name for RIC / RIT / RITE

Caregiver: Caregivers invest time, money, and emotion helping a friend or loved one manage loss of sight. The support might be as simple as listening but it can become much more, from managing finances and schedule to assisting with all ADL’s. Caregiving is what someone with disability desires – assistance with things they can no longer readily accomplish but not coddling or babying.

Caretaker: In modern usage, caretaker is sometimes used with the same sense as caregiver, but it’s more commonly used for a person who looks after property or for designating a government, administration, etc., in office temporarily.

Cataract Awareness Month: June. Cataract is the world’s leading cause of blindness, accounting for approximately 42% of all cases of blindness in all nations. 

Cataract Surgical Coverage (CSC-Eye) measures the proportions of eyes pinhole blind due to cataract, which have been operated so far. The numerator includes all (pseudo) aphakic eyes. The denominator includes the numerator, plus eyes pinhole blind due to cataract. Besides this, the indicator can also be calculated separately for PinVA <6/60 and <6/18.

Cataract Surgical Coverage (CSC-Person) indicates how many persons received cataract surgery (one or both eyes) among all who were bilaterally pinhole blind due to cataract. The numerator includes persons with one operated and one pinhole blind eye and persons with bilateral (pseudo) aphakia. The denominator includes the numerator, plus persons bilaterally pinhole blind due to cataract. Besides this, the indicator can also be calculated separately for PinVA <6/60 and <6/18.

Central Rehabilitation Register (CRR) is the registry of professionals, as managed by Rehabilitation Council of India, for providing rehabilitations services

Certified Orientation and Mobility Specialist (COMS) is a professional that instructs individuals who are blind or visually impaired with safe and effective travel through their environment. They support learners at home, in schools, and in the community.

Children’s Eye Health and Safety Awareness Month: August.

Child of Deaf Adults (CODA) is a person who was raised by one or more deaf parents or guardians. 90% of children born to deaf adults can hear normally, resulting in a significant and widespread community of codas around the world, although whether the child is hearing, D/deaf, or HH (hard of hearing) has no effect on the definition. The acronym KODA (Kid Of Deaf Adult) is sometimes used to refer to codas under the age of 18.

The term was coined by Millie Brother who also founded the organization CODA, which serves as a resource and a center of community for children of deaf adults as an oral and a sign language, and bicultural, identifying with both deaf and hearing cultures. Codas often navigate the border between the deaf and hearing worlds, serving as liaisons between their deaf parents and the hearing world in which they reside.

Children With Hearing Impairment (CWHI): 

Children With Special Needs (CWSN): 

Closed-Circuit TV / Caption Television (CCTV): An electronic system for capturing and projecting an enlarged image onto a screen or monitor. Also referred to as video magnifier.

Cochlear Implant (CI) is a small electronic device that electrically stimulates the cochlear nerve (nerve for hearing). The implant has external and internal parts. The external part sits behind the ear. It picks up sounds with a microphone. It then processes the sound and transmits it to the internal part of the implant.

Completely-In-Canal (CIC) ITE Hearing Aid

Comprehensive Evaluation: An assessment evaluating a student’s cognitive, emotional, social, physical, and academic development to determine whether the student is qualified to receive special education services. Specifically identifies a student’s strengths and needs.

Congenital Blindness refers to loss of vision present at birth (or within an early age like 5 years).

Continuing Rehabilitation Education (CRE) managed by RCI

Convention on the Rights of Persons with Disabilities (CRPD): 

Cortical/Cerebral Visual Impairment (CVI) is a neurological condition related to the visual pathway making it difficult for a person to interpreting visual information. Cortical Visual Impairment refers to the visual pathways going from the eye to the visual cortex. Cerebral Visual Impairment can encompass other areas of the brain, and also lower parts of the brain like the cerebellum.

Deaf usually refers to a hearing loss so severe that there is very little or no functional hearing

Deaf Aid: Same as Hearing Aid

Deaf Community: Members of the Deaf community tend to view deafness as a difference in human experience rather than a disability or disease. Many members take pride in their Deaf identity

Deaf Culture is the set of social beliefs, behaviors, art, literary traditions, history, values, and shared institutions of communities that are influenced by deafness and which use sign languages as the main means of communication. When used as a cultural label especially within the culture, the word deaf is often written with a capital D and referred to as "big D Deaf" in speech and sign. When used as a label for the audiological condition, it is written with a lower case d. Carl G. Croneberg coined the term "Deaf Culture" and he was the first to discuss analogies between Deaf and hearing cultures in his appendices C/D of the 1965 Dictionary of American Sign Language.

Deaf Identity: A deaf identity is about acknowledging the hearing loss, learning new ways to interact (and possibly some new skills) and being proud of what makes you different to hearing people, but also different from other deaf people.

Deaf or Hard of Hearing (DHH)

Deafblind (Db): Being deafblind is recognized as a unique disability in its own right. Any combination of documented hearing and vision loss, ranging from mild to profound hearing loss and low vision to total blindness. It doesn't necessarily mean that you are totally deaf or totally blind – most individuals who are deafblind have some residual sight and/or hearing. 

Deafblind Awareness Week: [USA] Established  in 1984, it is observed in the last week in June, in honor of Helen Keller's birthday on June 27th.

Deafened usually refers to a person who becomes deaf as an adult and, therefore, faces different challenges than those of a person who became deaf at birth or as a child.

Decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a power ratio of 101/10 (approximately 1.26)

Disability Adjusted Life Years (DALY) is a measure of overall disease burden, expressed as the number of years lost due to ill-health, disability or early death. It was developed in the 1990s as a way of comparing the overall health and life expectancy of different countries. 

DALY not only includes the potential years of life lost due to premature death, but also includes equivalent years of 'healthy' life lost by virtue of being in states of poor health or disability. In so doing, mortality and morbidity are combined into a single, common metric. It is a societal measure of the disease or disability burden in populations. DALYs are calculated by combining measures of life expectancy as well as the adjusted quality of life during a burdensome disease or disability for a population. DALYs are related to the Quality-Adjusted Life Year (QALY) measure; however, QALYs only measure the benefit with and without medical intervention and therefore do not measure the total burden. Also, QALYs tend to be an individual measure, and not a societal measure.

Traditionally, health liabilities were expressed using one measure, the Years of Life Lost (YLL) due to dying early. A medical condition that did not result in dying younger than expected was not counted. The burden of living with a disease or disability is measured by the Years Lost due to Disability (YLD) component, sometimes also known as years lost due to disease or years lived with disability/disease.

DALYs are calculated by taking the sum of these two components: DALY = YLL + YLD

The DALY relies on an acceptance that the most appropriate measure of the effects of chronic illness is time, both time lost due to premature death and time spent disabled by disease. One DALY, therefore, is equal to one year of healthy life lost.

Differently-abled: An old term for People with Disabilities (See How to refer to a Person with Disability? in Home page)

Diagnostic and Statistical Manual of Mental Disorders (DSM-5)

Digital Accessible Information SYstem (DAISY) is a format of digital materials that meets international standards for accessibility, by enhancing navigation and supporting text/audio synchronization. DAISY files require specialized software or devices to read. 

Digital Audio Books: May be human voice or computer synthesized voice, available in multiple formats. Can be played on a computer or a digital audio player (many off-the-shelf digital audio players do not offer full accessibility or are not compatible with all formats). 

Digital Book Player: Stand-alone device or computer software that provides access to digital talking books specifically developed for individuals with disabilities, with advanced features such as changing the audio output speed, navigating and searching the file. 

Digital Recorder: A portable electronic audio recorder that saves recorders in digital format, allowing the user to save and manage files on a computer. Digital recorders may be used as part of the writing process or to capture information from lectures or lessons. 

Digital Text: Digital Text or eText is a electronic version of a written text. Digital Text can be found on the internet or on your computer or on a variety of hand-held electronic devices. It can be searched, rearranged, condensed, annotated or read aloud by a computer.

Disabled Rights Group (DRG)

Disability Pride has been defined as accepting and honoring each person's uniqueness and seeing it as a natural and beautiful part of human diversity. Disability Pride is an integral part of movement building, and a direct challenge of systemic ableism and stigmatizing definitions of disability.

District Primary Education Programme (DPEP)

Document camera: A system for capturing images of a document or object and projecting onto a monitor or screen. Typically used by the general population and frequently lacks the advanced features of video magnifiers. 

DSI: Dual-Sensory Impairment: Or Multi-Sensory Impairment (MSI) are other terms that may be used if you have both sight and hearing impairments.

ECCE: Early Childhood Care and Education: Early childhood is a period that covers the first six years of a life of a child, wherein their brain grows at an extraordinary speed. ECCE is a multidisciplinary field that relies on insights from several fields like human development, psychology, sociology, and medicine, particularly neuroscience. 

Early Intervention (EI): Programs for young children with special needs, from birth until three. early intervention services may include speech therapy, occupational therapy, physical therapy, or other appropriate interventions which are typically provided in the child's home or a community setting.

Earmuffs are clothing accessories or personal protective equipment designed to cover a person's ears for hearing protection or for warmth. 

Earplug is a device that is inserted in the ear canal to protect the user's ears from loud noises, intrusion of water, foreign bodies, dust or excessive wind. 

Early Visual Impairment (EVI): VA < 6/12 – 6/18 in better eye with available correction, according to the Blindness and Visual Impairment Definitions in India.

Electric acoustic stimulation (EAS) is the use of a hearing aid and a cochlear implant technology together in the same ear. 

E-text: Electronic Text: Any text available in digital format, which can be accessed electronically (i.e. through computer or other mobile devices). Appearance of e-text can typically be modified by changing font, size, or text and background colors. Standard large font is from 18 to 24 pt. 

Employment Specialist: This individual works with the person who has lost their sight to ensure they know how to use technology such as JAWS which will enable them to re-join the workforce. They will also work with potential employers to ensure that appropriate accommodations are in place for an effective engagement. Lastly, they will work with the hiring manager and departmental staff as necessary to ensure that everyone is comfortable with how to interact. This is an essential function as both parties are likely to be initially uncomfortable and just a bit of guidance can help immeasurably.

Enabling Technology: Same as Assistive Technology.

Enlarged Text: A process of enlarging text for low vision readers that can be accomplished by changing the font on electronic files or through the use of a copy machine. 

ECC B/VI: Expanded Core Curriculum: The term expanded core curriculum (ECC) is used to define concepts and skills (compensatory or functional academic skills, including communication modes, orientation and mobility, social interaction skills and others) that often require direct specialized support for learners with visual impairments.

Fixation: Fixation or visual fixation is the maintaining of the visual gaze on a single location. Fixation, in the act of fixating, is the point between any two saccades, during which the eyes are relatively stationary and virtually all visual input occurs.

Functional Low Vision (FLV): A person with impairment of visual functioning even after treatment and/or standard refractive correction, and a VA of less than 6/18 to light perception, or a visual field of less than 10 degree from the point of fixation, but who uses, or is potentially able to use, vision for planning and/or execution of a task. This is according to the Blindness and Visual Impairment Definitions in India.

Functional Vision Assessment (FVA): An assessment, conducted by a teacher of students with visual impairments (TVI), to determine how a child uses their vision in everyday life. Based on the results, the TVI can make recommendations about ways to help your child learn to use his vision more effectively. Due to possible vision changes as the learner grows, it needs to be repeated periodically.

Fundus: The fundus is the inside, back surface of the eye. It is made up of the retina, macula, optic disc, fovea and blood vessels. With fundus photography, a special fundus camera points through the pupil to the back of the eye and takes pictures.

Glaucoma Awareness Month: January. 

Global Accessibility Awareness Day: 3rd Thursday of May

Global Positioning System (GPS): A satellite navigation system commonly used by drivers to determine position, direction, and assist with navigation. Devices or software with GPS capabilities may help an individual with visual impairment move more independently and safely throughout their community. 

Global Vision Database (GVD): The goal of the GVD is to develop and deploy new and improved evidence on the prevalence of blindness and vision impairment and its causes, on intervention coverage, to inform and influence global priorities and programs. 

Handheld Magnifier: A small, portable, low tech device that can be used to provide immediate magnification or illumination. Range in magnification from 2x to 16x, and should be prescribed by a low vision specialist. 

Haptics: Haptics is the science of applying touch (tactile) sensation and control to interaction with computer applications. One familiar example is when your phone is set on vibrate. Haptics are being used increasingly in enabling technology solutions, including canes that vibrate when you’re approaching an impediment or shoes which vibrate on one side or the other to tell the wearer which way to turn.

Hard of hearing refers to a hearing loss where there may be enough residual hearing that an auditory device, such as a hearing aid or FM system, provides adequate assistance to process speech.

Hearing Aid: Hearing aids are small electronic devices that can be highly customized to address different types of hearing loss. All digital hearing aids contain at least one microphone to pick up sound, a computer chip that amplifies and processes sound, a speaker that sends the signal to your ear and a battery for power. More sophisticated models provide additional features, such as direct connection to a smartphone or neural networks.  

Hearing Aid Applications (HAA) are software which, when installed on mobile computational platforms, transforms them into hearing aids

Hearing Impaired (HI) is describes people with any degree of hearing loss, from mild to profound, including those who are deaf and those who are hard of hearing. Many individuals who are deaf or hard of hearing prefer the terms "deaf" and "hard of hearing," because they consider them to be more positive than the term "hearing impaired," which implies a deficit or that something is wrong that makes a person less than whole.

Hearing Impairment 

Hearing Implant: It is a hearing device that is typically implanted into the ear. They are electronic devices that can be surgically placed in the ear to prevent hearing loss and deafness. Hearing implants are implanted in the inner part of the ear of patients that suffer from mild to severe deafness. 

Helen Keller Day: [USA] Commemorated on 27th June, the birthday of Hellen Keller. It celebrates the life and achievements of Helen Keller, a woman who overcame blindness and deafness and became infamous in the process.

Hyperacusis is the increased sensitivity to sound and a low tolerance for environmental noise 

Helix is the prominent rim of the auricle

In-The-Canal (ITC) ITE Hearing Aid

In-The-Ear (ITE) Hearing Aid

Inclusive Education for Disabled (IED)

Indian Scale for Assessment of Autism (ISAA)

Indian Sign Language (ISL)

Indian Sign Language Research and Training Centre (ISLRTC)

Individual Education Program Plan (IEP) is a written plan/program developed by the schools special education team with input from the parents and specifies the student's academic goals and the method to obtain these goals.

Individuals with Disabilities Education Act (IDEA), USA. A federal law that details the educational rights and requirements applicable to students with disabilities.

Inherited Retinal Diseases (IRD) are a group of diseases that can cause severe vision loss or even blindness. Each IRD is caused by at least one gene that is not working as it should

Integrated Education for Disabled Children (IEDC)

Intervention Specialist (IS): A certified teacher that assist learners with special education and social emotional needs in the classroom. They collaborate with team members to provide and assess individual education programs for learners.

Invisible-In-the-Canal (IIC) ITE Hearing Aid

International Classification of Disease (ICD) of the World Health Organization

International Guide Dog Day: Last Wednesday in April. References to guide dogs date back to at least the 16th century, so for the hundreds of years of service that these faithful companions have provided, this day is the thanks giving.

(The) International Year of Disabled Persons (IYDP): 1981. In 1976, the General Assembly proclaimed 1981 as the International Year of Disabled Persons (IYDP). It called for a plan of action at the national, regional and international levels, with an emphasis on equalization of opportunities, rehabilitation and prevention of disabilities.

International Year of Light: 2015. IYL 2015 was a United Nations observance that aimed to raise awareness of the achievements of light science and its applications, and its importance to humankind, specifically the visually impaired.

Intersectionality is an analytical framework for understanding how aspects of a person's social and political identities combine to create different modes of discrimination and privilege. Intersectionality identifies multiple factors of advantage and disadvantage. Examples of these factors include gender, caste, sex, race, ethnicity, class, sexuality, religion, disability, weight, physical appearance, and height. These intersecting and overlapping social identities may be both empowering and oppressing. The term was coined by Kimberlé Crenshaw in 1989. 

Ishihara Color Vision Test: It is a color perception test for red-green color deficiencies, the first in a class of successful color vision tests called pseudo-isochromatic plates ("PIP"). It is named after its designer, Shinobu Ishihara, a professor at the University of Tokyo, who first published his tests in 1917.

Keratoconus: Keratoconus occurs when your cornea — the clear, dome-shaped front surface of your eye — thins and gradually bulges outward into a cone shape. A cone-shaped cornea causes blurred vision and may cause sensitivity to light and glare.

Legally Blind: According to Blindness and Visual Impairment Definitions in US, legally blind means a level of vision loss with central visual acuity of 20/200 or less in the better eye with best possible correction, and/or a visual field of 20 degrees or less (Key definitions of statistical terms, 2013). 

Low Vision: Vision loss that cannot be corrected by medical or surgical procedures, or with conventional eyeglasses. The term used interchangeably with “visually impaired”. According to Blindness and Visual Impairment Definitions in US, low vision refers to a severe visual impairment in which visual acuity is 20/70 or poorer in the better-seeing eye and cannot improve with glasses or contacts.

Low Vision Awareness Month: February

Middle Ear Implants (MEI): It is a hearing device that is surgically implanted into the middle ear. They help people with conductive, sensorineural or mixed hearing loss to hear. Middle ear implants work by improving the conduction of sound vibrations from the middle ear to the inner ear. There are two types of middle ear devices: Active Middle Ear Implants (AMEI) and Passive Middle Ear Implants (PMEI).

MSVI: Moderate Severe Visual Impairment: VA < 6/18 – 3/60 in better eye with available correction, according to the Blindness and Visual Impairment Definitions in India.

MVI: Moderate Visual Impairment: VA < 6/18 – 6/60 in better eye with available correction, according to the Blindness and Visual Impairment Definitions in India.

Monocular: A handheld device similar to a telescope, generally used to improve visual clarify from a distance. 

Mountbatten Brailler: The Mountbatten Brailler is the complete Braille learning center for children and their teachers. As a professional resource, the Mountbatten Brailler offers exceptional connectivity and software to support flexible teaching and educational needs.

MSI: Multi-Sensory Impairment: Or Dual-Sensory Impairment (DSI) are other terms that may be used if you have both sight and hearing impairments.

MDVI: Multiple Disabilities and Visual Impairment: MDVI is a condition whereby an individual has vision impairment along with other disability/disabilities. Sometimes it may be a combination of two, three or even more impairments.  

NCPFECCE: National Curricular and Pedagogical Framework for Early Childhood Care and Education: According to NEP 2020, NCERT will develop a NCPFECCE for children up to the age of 8 . ECCE will be delivered through a significantly expanded and strengthened system of institutions including Anganwadis and pre-schools that will have teachers and Anganwadi workers trained in the ECCE pedagogy and curriculum. The planning and implementation of ECCE will be carried out jointly by the Ministries of Education, Women and Child Development (WCD), Health and Family Welfare (HFW), and Tribal Affairs.

National Disability Employment Awareness Month: [USA] October.

National Education Policy (NEP) 2020, Ministry of Education 

National Guide Dog Month: September. The purpose of this month long celebration is to raise awareness, support and appreciation for guide dog schools.

National Library Service for the Blind and Physically Handicapped (NLS):

NPCBVI: National Programme for Control of Blindness & Visual Impairment

Near-Field Communication (NFC): It is a set of communication protocols for communication between two electronic devices over a distance of 4 cm (11⁄2 in) or less. NFC offers a low-speed connection with simple setup that can be used to bootstrap more-capable wireless connections. What's an NFC Tag?

Nemeth Code: Braille code for writing mathematical and scientific notations, using the 6-dot Braille system. 

Noise-Induced Hearing Loss (NIHL) is caused by exposure to harmful, loud noise. This condition can affect people of all ages, and it may be temporary or permanent. You can take steps to prevent noise-induced hearing loss, such as wearing ear protection when necessary.

Notetakers: Electronic notetakers are small, portable devices for storing information with the use of braille or typewriter keyboards. 

OCALI: OCALI is a recognized global leader in creating and connecting resources and relationships to ensure that people with disabilities have the opportunity to live their best lives for their whole lives.

Ophthalmologist: A physician specializing in the treatment of diseases of the eye.

OBR: Optical Braille Recognition: OBR is the act of capturing and processing images of braille characters into natural language characters. It is used to convert braille documents for people who cannot read them into text, and for preservation and reproduction of the documents.

OCR: Optical Character Recognition: A process of converting images to digital text, allowing text images to be read, edited or otherwise manipulated. Some specialized software or devices incorporate OCR to enable text-to-speech capabilities. 

Optometrists: A healthcare professional who provides primary vision care ranging from vision testing and correction to the diagnosis, treatment, and management of vision changes.

Oralism is "advocacy or use of the oral method of teaching the deaf" (Merriam-Webster dictionary). Oralism consists of various methods used in teaching the deaf how to read lips by recognizing formations of the mouth in spoken dialogue, practicing certain breathing patterns used to produce words and letters, and mimicking mouth shapes. 

Organizations of Persons with Disabilities (DPO) 

O&M: Orientation and Mobility: The process of learning to safely and independently travel throughout one’s environment, while reinforcing concepts about body, space, direction and movement. 

Otalgia, also known as earache or Ear pain, is pain in the ear. Primary ear pain is pain that originates from the ear. Secondary ear pain is a type of referred pain, meaning that the source of the pain differs from the location where the pain is felt. 

PMEI: Passive Middle Ear Implants replace damaged or missing parts of the middle ear, creating a bridge between the outer ear and the inner ear, so that sound vibrations can be conducted through the middle ear and on to the cochlea. Unlike AMEIs, PMEIs contain no electronics and are not powered by an external source.

Parent Mentor: A professional who is a parent of a child with a disability specially trained to support and mentor other parents experiencing similar circumstances. 

Partially Sighted: According to Blindness and Visual Impairment Definitions in US, partially sighted means a person has partial vision, either in one or both eyes.

Perkins Brailler: The Perkins Brailler is a "braille typewriter" with a key corresponding to each of the six dots of the braille code, a space key, a backspace key, and a line space key. Like a manual typewriter, it has two side knobs to advance paper through the machine and a carriage return lever above the keys. The rollers that hold and advance the paper have grooves designed to avoid crushing the raised dots the brailler creates.

PBVI: Persons with Blindness or Visual Impairment

PwD: Person with Disability

Person-first Language: The phrasing can initially be difficult but you always want to place modifiers such as blind after person rather than vice-versa. Perhaps an example will help. It is easiest to say “a blind person” but person-first language suggests you should say “a person who is blind”. Blindness is an aspect of their humanity but it doesn’t segment and categorize them. This concept arose in disability discussions but is applicable in so many other settings.

PDA: Personal Digital Assistants: PDAs are small networked computers which can fit in the palm of your hand. PDAs have evolved over the years, beginning with first-generation devices such as the Apple Newton (Apple coined the term “PDA”) and Palm Pilot. 

PSAP: Personal Sound Amplification Products or Personal Sound Amplification Devices are defined by the U.S. Food and Drug Administration as wearable electronic products that are intended to amplify sounds for people who are not d/Deaf or Hard of Hearing. They are not hearing aids, which the FDA describes as intended to compensate for hearing loss. 

Pinna: Same as Auricle

PEF: Portable Embosser File (PEF): PEF is a document type that represents braille pages in digital form, accurately and unambiguously; regardless of language, location, embosser settings, braille code and computer environment.

Print Disability: A print disability is a difficulty or inability to read printed material due to a perceptual, physical or visual disability. The reasons for print disability vary but may include: vision impairment or blindness. physical dexterity problems such as multiple sclerosis, Parkinson's disease, arthritis or paralysis.

Pursuits: In the study of vision, smooth pursuit describes a type of eye movement in which the eyes remain fixated on a moving object. It is one of two ways that visual animals can voluntarily shift gaze, the other being saccadic eye movements. 

RAAB: Rapid Assessment of Avoidable Blindness: It is a rapid survey methodology. It is a population based survey of blindness and visual impairment and eye care services among people aged 50 years and over.

RIC / RIT / RITE: Receiver-In-Canal / Receiver-In-Ear BTE Hearing Aid

Refreshable Braille Display: A device that can display Braille characters using a dynamic system of dots that can be raised. Can be used with a computer or other devices to allow the user to read digital text through Braille. 

Rehabilitation Council of India (RCI) was set up as a registered society in 1986. On September,1992 the RCI Act was enacted by Parliament and it became a Statutory Body on 22 June 1993. The mandate given to RCI is to regulate and monitor services given to persons with disability, to standardize syllabi and to maintain a Central Rehabilitation Register (CRR) of all qualified professionals and personnel working in the field of Rehabilitation and Special Education. 

Right to Education (RTE) Act, 2009

Saccades: Saccades are rapid, ballistic movements of the eyes that abruptly change the point of fixation. They range in amplitude from the small movements made while reading, for example, to the much larger movements made while gazing around a room.

Sarva Siksha Abhiyan (SSA)

Screen Magnification: Enlargement of computer screen content using software. Depending on the software, may provide audio feedback, allow for color enhancement, or modify cursor and pointer. Some software will enlarge the individual items on the screen, maintaining the screen integrity, while others zoom in on only one section of the screen, requiring the user to navigate to the unseen portions of the screen. 

Screen Reader: Digital content of a computer monitor (i.e. text, icons, graphics) are read by software in an audio format. 

SVI: Severe Visual Impairment: VA < 6/60 – 3/60 in better eye with available correction, according to the Blindness and Visual Impairment Definitions in India.

Slate and Stylus: A low tech template and punch which allows the user to create Braille on a paper. Not commonly used. 

Snellen Chart: It is an eye chart that can be used to measure visual acuity and is named after the Dutch ophthalmologist Herman Snellen, who developed the chart in 1862. Improvements are known as the LogMAR chart.

SEND: Special Educational Needs and Disabilities: SEND can affect a child or young person's ability to learn. They can affect their: behavior or ability to socialize, for example they struggle to make friends, reading and writing, for example because they have dyslexia.

Specially Designed Instruction (SDI): Teaching methods and strategies specific towards educating children with disabilities, to allow them to access the curriculum and meet the standards for his or her grade level. This is done by either adapting the content, adapting the methodology, or adapting the delivery of instruction. Specially designed instruction often involves multiple team members to provide access to the curriculum for children with disabilities.

Speech Generating Devices (SGD): Also known as Voice Output Communication Aids (VOCA)

Sonification: It is the use of non-speech audio to convey information or perceptualize data. Auditory perception has advantages in temporal, spatial, amplitude, and frequency resolution that open possibilities as an alternative or complement to visualization techniques. For example, the rate of clicking of a Geiger counter conveys the level of radiation in the immediate vicinity of the device.

Speech-to-Text: Software that converts spoken word into text through a process known as “dictation”, or allows voice-activated access to a computer through “commands”. 

SHI: Speech and Hearing Impaired

Stereoscopy: Stereoscopy (also called stereoscopics, or stereo imaging) is a technique for creating or enhancing the illusion of depth in an image by means of stereopsis for binocular vision. These two-dimensional images are then combined in the brain to give the perception of 3D depth.

Tactual Reading: Another term for reading through the use of Braille. 

Talking Calculator: A talking calculator has a built-in speech synthesizer that reads aloud each number, symbol, or operation key a user presses; it also vocalizes the answer to the problem.

TVI: Teacher of Students with Visually Impaired: Also called a Teacher of the Visually Impaired, a Vision Specialist, VI Teacher, Vision Itinerant Teacher. She / he is typically a licensed special education teacher who has received certification and specialized training, in meeting the educational needs of students who are who are blind or have visual impairments ages birth through adulthood.

TTS: Text-To-Speech: Software that allows the computer to “read” text out loud using digitized voice. May be used to access digital text (i.e. documents, websites) or in conjunction with writing (i.e. talking word processor). Some versions include tracking support, where text is highlighted as it is read by the computer. 

Tinnitus is the perception of sound when no corresponding external sound is present. Nearly everyone will experience a faint "normal tinnitus" in a completely quiet room but it is only of concern if it is bothersome or interferes with normal hearing or correlated with other problems. While often described as a ringing, it may also sound like a clicking, buzzing, hiss, or roaring. The sound may be soft or loud, low or high pitched, and often appears to be coming from one or both ears or from the head itself. 

Totally Blind: According to Blindness and Visual Impairment Definitions in US, totally blind refers to a complete loss of sight.

UEB: Unified English Braille Code: It is an English language Braille code standard, developed to permit representing the wide variety of literary and technical material in use in the English-speaking world today, in uniform fashion.

Usher Syndrome, also known as Hallgren syndrome, is a rare genetic disorder caused by a mutation in any one of at least 11 genes resulting in a combination of hearing loss and visual impairment. It is a major cause of deafblindness and is at present incurable.

Video Magnifier: Using a video camera, an image is captured and projected onto a video monitor or TV screen. May be used with documents, while writing or completing a fine motor task, or to view objects. Some video magnifiers have cameras that can be repositioned to view other parts of the classroom (“room viewing”). 

VLEG: Vision Loss Expert Group: VLEG is an international group of ophthalmologists and optometrists with experience in ophthalmic epidemiology. VLEG provides global technical leadership in the development and improvement of epidemiological estimates for blindness and vision impairment. VLEG populates and curates the Global Vision Database (GVD).

VA: Visual Acuity: It refers to your ability to discern the shapes and details of the things you see. It's just one factor in your overall vision. Others include color vision, peripheral vision, and depth perception. There are several different types of visual acuity tests, most of which are very simple.

Vertigo is a condition where a person has the sensation of movement or of surrounding objects moving when they are not. Often it feels like a spinning or swaying movement.

VI: Visual Impairment: A general description of significant vision loss. May include individuals with low vision, legal blindness, or total blindness. Clinically, visual impairment is defined as a visual acuity of 20/70 or worse in the best eye with correction, or total visual field loss of 140 degrees. A condition of the eye or visual system that results in a reduced vision due to limited visual acuity or visual field that cannot be corrected using standard corrective lenses. 

VR: Vocational Rehabilitation: A program that provides services and supports necessary to help individuals with disabilities attain and maintain employment.

Voice Output Communication Aids (VOCA): Also known as Speech Generating Devices (SGD)

World Braille Day (WBD) is an international day on 4th January and celebrates awareness of the importance of braille as a means of communication in the full realization of the human rights for blind and visually impaired people. It marks the birthday of Louis Braille on 1809. 

In India it is also called Louis Braille Day when a blind person reads news on Doordarshan and All India Radio.

World Disabled Day: International Day of Persons with Disabilities on 3rd December. The observance of the Day aims to promote an understanding of disability issues and mobilize support for the dignity, rights and well-being of persons with disabilities. It also seeks to increase awareness of gains to be derived from the integration of persons with disabilities in every aspect of political, social, economic and cultural life.

World Glaucoma Day: 12th March. It is observed to raise awareness about glaucoma and to alert everyone to have regular eye (and optic nerve) check-ups to detect glaucoma as early as possible. Glaucoma is one of the leading causes of irreversible blindness, but with early treatment, the damage may get limited and sight may be saved.

World Health Day: 7th April. It is celebrated annually and each year draws attention to a specific health topic of concern to people all over the world. The date of 7 April marks the anniversary of the founding of WHO in 1948.

World Sight Day (WSD) is an annual day of awareness held on the second Thursday of October, to focus global attention on blindness and vision impairment, raise public awareness of blindness & vision impairment, influence Governments/Ministers of Health to participate in and designate funds for national blindness prevention programmes and educate target audiences about blindness prevention. Most often it has a theme to focus activities on:

World Federation of the Deaf (WFD)

World Health Organization (WHO) was founded in 1948. It is the United Nations agency that connects nations, partners and people to promote health, keep the world safe and serve the vulnerable – so everyone, everywhere can attain the highest level of health. 

World Usability Day: Second Thursday in November. Also called Make Things Easier Day, it is observed annually to promote the values of usability, usability engineering, user-centered design, universal usability, and every user's responsibility to ask for things that work better. 

World White Cane Safety Day: 15th October. The date is set aside to celebrate the achievements of people who are blind or visually impaired and the important symbol of blindness and tool of independence, the white cane.

Years of Life Lost (YLL) is an estimate of the average years a person would have lived if they had not died prematurely. It is, therefore, a measure of premature mortality. As an alternative to death rates, it is a method that gives more weight to deaths that occur among younger people. An alternative is to consider the effects of both disability and premature death using disability adjusted life years. It is also called Years of Potential Life Lost (YPLL) or Potential Years of Life Lost (PYLL). YLL is used to compute DALY.

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