Glossary
Searchable terminology from accessibility, web standards, and related fields.
78 results found in Visual Accessibility.
- Luminous Efficiency Function (LEF, Spectral Luminous Efficiency Function, V(lambda))
- A function that describes how the human visual system converts light intensity at different wavelengths into perceived brightness. The standard LEF used in WCAG contrast ratio calculations is based on…
- Magnification Factor (Zoom Level, Magnification Level, Zoom Factor)
- The ratio by which screen content is enlarged when using a screen magnifier. A magnification factor of 2x means the content appears twice its original size, but only one quarter of the original screen…
- Map Accessibility (Accessible maps)
- The practice and field of making maps — digital geovisualizations, online navigation maps, tactile maps, and physical signage — perceivable, operable, understandable, and robust for users with disabil…
- Menu Selection (Menu Navigation, Menu Selection Task)
- A fundamental computer interaction task in which a user chooses an option from a set of items presented in a menu structure, typically involving locating the target item, moving the cursor to it, and …
- Mouse Pointer (Cursor, Screen Pointer, Onscreen Pointer)
- The small graphical indicator on a computer screen that represents the position of a pointing device such as a mouse, trackpad, or stylus. The mouse pointer is used to identify and interact with inter…
- Non-Visual Interaction (Non-Visual Access, Non-Visual Interface)
- Methods of interacting with computer systems and digital content without relying on visual display. Non-visual interaction encompasses screen reader output, speech interfaces, keyboard navigation with…
- Non-Visual Mental Model (Non-Visual Representation, Tactile Mental Model)
- A cognitive representation of concepts, objects, or systems built through non-visual sensory channels — primarily touch, hearing, and proprioception — rather than through sight. People who are blind d…
- Non-Visual Reading (Audio Reading, Tactile Reading)
- Methods of accessing written content without relying on visual perception, including braille reading, screen reader audio output, and text-to-speech technology. Non-visual reading is essential for bli…
- Non-visual Display (Nonvisual Display, Non-visual Interface)
- A non-visual display presents information to a user through senses other than vision — most commonly hearing (synthesized speech, earcons, sonification), touch (Braille output, vibrotactile patterns, …
- Page Magnification (Page Zoom, Web Page Magnification)
- An accessibility feature that enlarges the entire visual presentation of a web page, including text, images, and layout elements, to make content easier to see for people with low vision or visual fat…
- Pattern Glare
- A visual perceptual phenomenon where repeated striped or lined patterns cause discomfort, headaches, eyestrain, or visual distortions such as flickering, shimmering, or apparent movement. Pattern glar…
- Precompensation (Display Precompensation, Image Precompensation)
- A technique in visual accessibility that pre-modifies displayed images in a way that is opposite to the optical distortion introduced by a user's eye, so that the image arriving at the retina more clo…
- Protanomaly (Protan Anomalous Trichromacy)
- A type of colour vision deficiency where the long-wavelength (red) cone cells have a shifted sensitivity range rather than being absent entirely. Protanomaly is a milder form of protan CVD compared to…
- Protanopia (Protan Dichromacy, Red-Blind)
- A type of colour vision deficiency caused by the complete absence of long-wavelength (red) cone cells in the retina. People with protanopia cannot distinguish between red and green and perceive reds a…
- Redundant Encoding (Redundant Coding, Multi-Channel Encoding)
- A design principle that communicates information through multiple visual channels simultaneously — such as colour plus shape, pattern, text label, or position — so that no single channel is required f…
- STEM Accessibility (Accessible STEM, STEM for Students with Disabilities)
- The design and delivery of science, technology, engineering, and mathematics education in ways that are accessible to students with disabilities. STEM accessibility is a particularly acute challenge f…
- School for the Blind (Blind School, Residential Blind School)
- A specialized educational institution that serves students with vision impairments, often as a residential facility where students live on campus. In India and other Global South countries, schools fo…
- Screen Magnification (Screen Magnifier, Display Magnification)
- Software or operating system features that enlarge a portion of the screen content to make it readable for people with low vision. Common modalities include full-screen magnification (which expands th…
- Screen Magnifier (Screen Magnification Software, Magnification Software)
- An assistive technology application that enlarges a portion of the screen display to make content more readable for people with low vision. Screen magnifiers work by rendering a zoomed-in view of the …
- Screen Reader Output (Screen Reader Speech)
- The audio or braille output generated by screen reader software as it interprets and conveys on-screen content to blind and low vision users. Screen reader output quality significantly impacts reading…