Glossary
Searchable terminology from accessibility, web standards, and related fields.
6660 terms — page 314 of 333
- Virtual audit (Remote audit, Virtual streetscape audit, GSV audit)
- A method of assessing the physical environment for accessibility features and barriers using street-level imagery such as Google Street View, rather than conducting in-person site visits. Virtual audi…
- Virtual environment (Virtual world, VR environment, 3D virtual space)
- A computer-generated simulation of a three-dimensional space that users can navigate and interact with, typically rendered visually through screens or head-mounted displays. Virtual environments range…
- Virtual reality (VR, Immersive virtual environment)
- A computer-generated simulation of a three-dimensional environment that users can interact with using specialized hardware such as head-mounted displays and motion controllers. Virtual reality present…
- Viseme (Visual Phoneme)
- The visual equivalent of a phoneme — the distinct mouth shape or lip position that corresponds to a speech sound as seen on a speaker's face. Unlike phonemes, which are auditory units, visemes are vis…
- Visible Disability (Apparent Disability)
- A disability that is readily apparent to outside observers through physical characteristics, mobility aids, or other visible indicators. Examples include amputations, paralysis, use of a wheelchair, o…
- Vision Impairment (Visual Impairment, VI)
- An umbrella term for any reduction in visual function — including low vision, blindness, and functional limitations that affect everyday tasks — regardless of cause. The World Health Organization dist…
- Vision Language Model (VLM, Vision-Language Model, Multimodal Large Language Model)
- A machine-learning model trained to take both images and natural-language text as input and to produce natural-language output. Modern VLMs — such as GPT-4o, Gemini, and Claude — can describe a photo,…
- Vision Multiplexing (Visual Multiplexing)
- An optical engineering concept for low-vision aids that involves presenting multiple views or visual channels simultaneously to compensate for reduced visual function. In the context of assistive tech…
- 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…
- Vision Therapy (Visual Training, Orthoptics, Eye Training)
- A program of visual activities and exercises prescribed to improve visual skills and processing, often used to treat conditions like amblyopia, strabismus, and convergence insufficiency. Vision therap…
- Vision User (VU, Sighted User)
- A person who primarily uses vision to access digital content, interacting with web pages and applications through visual scanning, mouse/trackpad pointing, and visual recognition of interface elements…
- Vision-Language Model (VLM, Multimodal AI Model, Large Multimodal Model)
- An artificial intelligence model that can process and reason about both visual (image/video) and textual information simultaneously. Vision-language models like GPT-4o, Claude, and Gemini can describe…
- Vision-and-Language Navigation (VLN)
- Vision-and-language navigation is a task setup in which an agent follows natural-language instructions to move through a visual environment, grounding words like 'turn left at the blue sofa' onto what…
- Vision-based Page Segmentation (VIPS)
- A web page segmentation algorithm that uses both the source code and the visual presentation of a web page to divide it into hierarchical visual blocks. VIPS produces a tree structure where the root n…
- Vista Space (Vista)
- In Montello's classification of psychological spaces, a Vista is a far-field space that can be visually apprehended from a single vantage point without appreciable locomotion - a horizon view, a city …
- Visual Aberration (Optical Aberration, Refractive Error)
- A deviation from ideal optical performance in the eye that causes images to appear blurred, distorted, or otherwise degraded on the retina. Visual aberrations include both lower-order aberrations (suc…
- Visual Access Technology (Visual Assistance Technology, Visual Access Tools)
- Technologies that help blind and low vision people understand visual content in both digital and physical environments. Traditional visual access technologies include screen readers, magnification sof…
- Visual Acuity
- A measure of the sharpness or clarity of vision, typically expressed as a fraction (e.g., 20/20) or percentage indicating the smallest detail a person can resolve at a standard distance. Visual acuity…
- 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 Aesthetics (Aesthetic Quality, Visual Appeal)
- The subjective qualities of visual content that contribute to its perceived beauty, mood, style, and emotional impact, including elements like color harmony, composition, lighting, contrast, and overa…