Glossary

Searchable terminology from accessibility, web standards, and related fields.

70 results found in low vision.

Tunnel Vision (Peripheral Vision Loss, PVL)
A visual impairment characterized by the loss of peripheral vision while central vision may remain intact, resulting in a narrow field of view as if looking through a tunnel. Tunnel vision can be caus…
Video Magnifier (CCTV Magnifier, Electronic Magnifier, Desktop Video Magnifier)
An assistive device that uses a camera to capture and display magnified images of printed material, objects, or other visual content on a screen. Video magnifiers range from portable handheld units to…
Vision Rehabilitation (Visual Rehabilitation)
See Low-Vision Rehabilitation. A comprehensive set of services and interventions designed to help people with vision loss maximize their remaining vision and develop adaptive strategies for independen…
Visual Acuity (VA, Sharpness of Vision)
A measure of the eye's ability to distinguish fine details and shapes at a given distance. Visual acuity is commonly expressed as a Snellen fraction (e.g., 20/20, 20/200) or in logMAR units used in cl…
Visual Fatigue (Eye Strain, Asthenopia, Visual Strain)
Discomfort, tiredness, or reduced visual performance resulting from prolonged or intensive visual tasks. For people with low vision, visual fatigue can occur more quickly because they must exert great…
Visual Field (Field of Vision)
The total area visible to a person when their eyes are fixated on a central point, including both central and peripheral vision. Visual field can be measured in degrees and is assessed through perimet…
Visual Search Strategy (Scanning Strategy, Visual Scanning)
Systematic approaches to visually exploring an environment or scene to locate specific objects, patterns, or information. In low-vision rehabilitation, therapists train clients in efficient search str…
Visual acuity (VA, LogMAR acuity, Snellen acuity)
A measure of the sharpness or clarity of vision, typically expressed as a Snellen fraction (e.g., 20/20, 20/200) or LogMAR value. A person with 20/200 vision must be 20 feet away to see what someone w…
Visual field loss (Peripheral vision loss, Scotoma, Tunnel vision, Visual field defect)
A reduction in the area of vision that a person can see, either in the periphery (peripheral vision loss or tunnel vision) or in the center (central vision loss or central scotoma). Visual field loss …
ZoomText
A commercial screen magnification and screen reading software for Windows, developed by Freedom Scientific (formerly Ai Squared). ZoomText provides up to 60x magnification along with features like smo…