Glossary
Searchable terminology from accessibility, web standards, and related fields.
74 results found in Visual Impairment.
- Nystagmus (Involuntary eye movement, Dancing eyes)
- A condition characterized by involuntary, repetitive, rhythmic movements of the eyes, which may move side to side (horizontal), up and down (vertical), or in a circular pattern (rotary). Nystagmus can…
- Nystagmus (Involuntary Eye Movement, Dancing Eyes)
- A condition involving involuntary, repetitive, and rhythmic movements of the eyes, which can be horizontal, vertical, or rotary. Nystagmus can be congenital (present from birth) or acquired later in l…
- Object Permanence
- The cognitive understanding that objects continue to exist even when they cannot be directly perceived through sight, sound, or touch. This developmental milestone, typically achieved in infancy for s…
- Orientation and mobility (O&M)
- A professional discipline and set of skills that enable people with visual impairments to travel safely and independently through their environment. Orientation refers to understanding one's position …
- Presbyopia (Age-Related Farsightedness)
- An age-related vision condition where the eye gradually loses its ability to focus on nearby objects, typically becoming noticeable in the early to mid-40s. Presbyopia affects virtually everyone as th…
- Residual vision (Functional vision, Usable vision)
- The remaining visual ability of a person with a visual impairment, which may include partial acuity, limited visual field, or light perception. The vast majority of people classified as legally blind …
- Restricted Field of View (Tunnel Vision, Peripheral Vision Loss, Visual Field Loss)
- A condition in which the area of the visual environment that a person can see at any given moment is significantly reduced, often described as looking through a tunnel or a narrow tube. Restricted fie…
- Retinitis Pigmentosa (RP)
- A group of inherited genetic disorders that cause progressive degeneration of the retina, typically beginning with loss of night vision and peripheral vision and potentially leading to tunnel vision o…
- Retinitis pigmentosa (RP)
- A group of inherited genetic disorders that cause progressive degeneration of the retina, typically beginning with loss of night vision and peripheral vision and gradually narrowing the visual field (…
- Retinopathy of Prematurity (ROP)
- An eye condition that can occur in premature infants when abnormal blood vessels grow in the retina. In severe cases, these vessels can cause scarring, retinal detachment, and significant vision loss …
- Scene simplification (Visual decluttering, Complexity reduction)
- An assistive technology approach that reduces visual complexity in real-world or digital scenes by highlighting relevant objects, suppressing background clutter, and isolating key information. Scene s…
- Scotoma (Blind Spot, Visual Field Defect)
- An area of partial or complete loss of vision within an otherwise normal visual field. Scotomas can be central (affecting the area of sharpest vision) or peripheral, and may be caused by conditions su…
- Screen magnifier (Screen magnification software, Zoom software)
- Assistive software that enlarges a portion of the screen display to make content visible for people with low vision. Users navigate the magnified view by panning with the mouse or keyboard, seeing onl…
- Semantic Bookmarking (Semantic Bookmark, Concept-Based Bookmarking)
- A web navigation technique that associates saved page locations with meaningful conceptual labels from a domain ontology rather than with specific structural positions in the HTML code. Unlike traditi…
- Sighted Assistance (Visual Interpreting, Remote Sighted Assistance)
- Sighted assistance refers to services that connect blind or low-vision individuals with sighted people who can provide visual information on demand, typically through a live video call from a smartpho…
- Simultanagnosia (Simultagnosia)
- A neurological condition in which a person can perceive individual objects but cannot see or process multiple objects simultaneously within a visual scene. Simultanagnosia is a common feature of cereb…
- Smart Glasses (AR Glasses, Assistive Smart Glasses)
- Smart glasses are head-mounted wearable devices that incorporate cameras, microphones, speakers, and computing capabilities into an eyeglass form factor. For people who are blind or have low vision, s…
- Split Tap (Split Tapping)
- A touchscreen interaction technique where the user holds one finger on a target element while tapping with a second finger to activate it. Split tap allows blind users to explore the screen with one f…
- Stargardt Disease (Stargardt Macular Dystrophy, Fundus Flavimaculatus)
- An inherited eye condition that causes progressive vision loss affecting the macula, the central part of the retina responsible for sharp, detailed vision. Stargardt disease typically begins in childh…
- Strabismus (Crossed eyes, Squint, Eye misalignment)
- A condition in which the eyes do not align properly, causing one eye to point in a different direction from the other — inward (esotropia), outward (exotropia or exophoria), upward, or downward. Strab…