Glossary
Searchable terminology from accessibility, web standards, and related fields.
74 results found in Visual Impairment.
- Glaucoma
- A group of eye diseases that damage the optic nerve, usually caused by abnormally high intraocular pressure. It is one of the leading causes of irreversible blindness worldwide, affecting over 80 mill…
- Glaucoma
- A group of eye conditions that damage the optic nerve, typically associated with elevated intraocular pressure. Glaucoma is a leading cause of irreversible blindness worldwide. It usually causes gradu…
- Hyperopia (Farsightedness, Long-Sightedness, Hypermetropia)
- A refractive error in which the eye focuses light behind the retina rather than on it, causing near objects to appear blurred while distant objects may remain relatively clear. Hyperopia occurs when t…
- Keratoconus
- A progressive eye condition in which the normally round cornea thins and bulges into a cone-like shape, causing irregular astigmatism and significant visual distortion that cannot be fully corrected w…
- Leber Hereditary Optic Neuropathy (LHON)
- A maternally inherited genetic condition that causes sudden or rapid loss of central vision, typically affecting young adults between the ages of 15 and 35. LHON results from mutations in mitochondria…
- Legal blindness (Legally blind)
- A level of visual impairment defined in many jurisdictions as visual acuity of 20/200 or worse in the better eye with best correction, or a visual field of 20 degrees or less. Legal blindness is an ad…
- Legally Blind (Legal Blindness)
- A legal classification of visual impairment used to determine eligibility for government benefits, rehabilitation services, and disability accommodations. In the United States, legal blindness is defi…
- Link Preview (Link Destination Preview, Link Target Preview)
- Information about the content or nature of a hypertext link's destination page, provided to users before they follow the link. Link previews help users make informed navigation decisions, reducing the…
- Live Description (Real-Time Description, Live Audio Description)
- The practice of providing descriptions of visual content in real time as events unfold, as opposed to scripted descriptions added during post-production of recorded media. Live description is used in …
- Livestream Accessibility (Live Video Accessibility)
- The practice of making live video broadcasts accessible to people with disabilities, particularly viewers with visual or hearing impairments. Livestreams present unique accessibility challenges becaus…
- LogMAR (Logarithm of the Minimum Angle of Resolution)
- A standardised scale for measuring visual acuity based on the logarithm (base 10) of the minimum angle of resolution, used in the Bailey-Lovie eye chart and widely adopted in clinical vision research.…
- Low Vision (Partial Sight, Partially Sighted)
- A visual impairment that cannot be fully corrected by glasses, contact lenses, medication, or surgery, but where some usable vision remains. Low vision encompasses a wide range of conditions and sever…
- Low vision (Partial sight, Visual impairment)
- A level of visual impairment that cannot be fully corrected with standard glasses, contact lenses, medication, or surgery, but retains some usable vision — distinguishing it from total blindness. Low …
- Macular Degeneration (AMD, Age-Related Macular Degeneration, ARMD)
- A progressive eye condition affecting the macula — the central part of the retina responsible for sharp, detailed vision. It is the leading cause of severe vision loss in people over 50 in developed c…
- Macular degeneration (AMD, Age-related macular degeneration, ARMD)
- A progressive eye disease that damages the macula, the central part of the retina responsible for sharp, detailed vision. It is the leading cause of vision loss in people over 50, affecting central vi…
- Marburg Notation (Marburg Mathematical Notation, Marburg Braille)
- A Braille-based mathematical notation system developed at the Deutsche Blindenstudienanstalt (German Institute for the Blind) in Marburg, Germany, and widely used in German-speaking countries for read…
- Meares-Irlen Syndrome (Irlen Syndrome, Visual Stress Syndrome, Scotopic Sensitivity Syndrome)
- Meares-Irlen Syndrome is a perceptual processing disorder that affects how the brain processes visual information, causing symptoms of visual stress including pattern glare, perceptual distortions, ey…
- Myopia (Nearsightedness, Short-Sightedness)
- A common refractive error in which the eye focuses light in front of the retina rather than on it, causing distant objects to appear blurred while near objects remain clear. Myopia occurs when the eye…
- NVDA (NonVisual Desktop Access)
- A free, open-source screen reader for Microsoft Windows developed by NV Access. NVDA enables people who are blind or have low vision to use computers by reading on-screen text aloud through a speech s…
- Neural Plasticity (Neuroplasticity, Brain Plasticity)
- The brain's ability to reorganize itself by forming new neural connections throughout life. In the context of accessibility, neural plasticity explains how people who are blind or visually impaired de…