Glossary
Searchable terminology from accessibility, web standards, and related fields.
6660 terms — page 316 of 333
- Visual Evoked Potential (VEP, Visually Evoked Response, VERP)
- A visual evoked potential (VEP) is an electrical signal generated by the brain's visual cortex in response to a visual stimulus, typically a flash of light or a pattern change. VEPs are measured using…
- Visual Expression (Visual Self-Expression)
- The use of visual media — including photography, graphic design, social media posts, presentations, and art — to communicate identity, mood, intent, and personal style. Visual expression goes beyond f…
- 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 Feedback (Visual Biofeedback)
- A method of providing real-time visual information to a user about their actions, performance, or physiological state. In speech therapy and assistive technology, visual feedback systems display graph…
- Visual Fidelity (Graphical Fidelity, VF)
- The degree to which a virtual environment replicates the visual detail, realism, and complexity of real-world settings. In accessibility contexts, visual fidelity affects cognitive load and task perfo…
- 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 Field Loss (Visual Field Deficit, VFL, Field Loss)
- A reduction in the area of vision that a person can see without moving their eyes or head. Visual field loss can affect any portion of the visual field — central, peripheral, or specific quadrants — a…
- Visual Fragmentation (Visual Grouping, Visually Fragmented Grouping)
- The design practice of organizing web page content into distinct visual groups using layout techniques such as background colors, tables, spacing, horizontal lines, and borders. Sighted users perceive…
- Visual Grounding (Grounded Visual Understanding)
- The ability of an AI model to connect its language output to specific elements actually present in the visual input, ensuring that descriptions and responses are anchored to real objects and scenes ra…
- Visual Hallucination (AI hallucination, MLLM hallucination)
- In the context of multimodal AI systems, visual hallucination refers to the generation of descriptions or responses that contain information not grounded in the actual visual input—fabricating non-exi…
- Visual Impairment (Vision Impairment, Low Vision, Sight Loss)
- A reduction in the ability to see that cannot be fully corrected with standard glasses, contact lenses, or medical treatment. Visual impairments range from low vision (partial sight) to total blindnes…
- Visual Inertial Odometry (VIO)
- A motion tracking technique that combines camera-based visual tracking with inertial sensor data (gyroscopes and accelerometers) to estimate a device’s position and orientation in 3D space with high a…
- Visual Information Seeking Mantra (Overview First, Shneiderman's Mantra)
- A design principle for information visualisation coined by Ben Shneiderman, summarised as "overview first, zoom and filter, then details-on-demand." The mantra describes an optimal pattern for present…
- Visual Interpretation (AI Visual Interpretation, Visual Interpretation Application)
- The task of translating visual content — a scene, object, document, interface, or image — into a form accessible to a blind or low-vision user, typically spoken or written description, answers to ques…
- Visual Interpretation Service (VIS, Visual Assistance Service, Remote Sighted Assistance)
- A service that provides visual information to blind and low vision users through human assistants, AI-powered tools, or a combination of both. Traditional visual interpretation services like Aira conn…
- Visual Interpretation Services (VIS, Remote Sighted Assistance, Visual Assistance Services)
- Visual interpretation services are technology platforms that connect blind and low vision users with sighted assistants (either human volunteers or paid professionals) who provide real-time visual des…
- Visual Interpreter (Visual Interpreter Service, Visual Description Service, VIDS, Remote Sighted Assistance)
- A visual interpreter or description service (VIDS) is a technology or human-powered service that provides people who are blind or have low vision with descriptions of their visual surroundings, typica…
- Visual Language (Visuo-Gestural Language)
- A language that uses the visual-gestural modality for communication, as opposed to the auditory-vocal modality of spoken languages. Sign languages are visual languages that encode information through …
- Visual Language Model (VLM, Vision-Language Model)
- AI models that can process and reason about both visual and textual information, combining computer vision with large language model capabilities. VLMs could potentially enhance assessment descriptors…
- Visual Layout Analysis (Layout Analysis, Document Layout Analysis)
- The automated process of examining the spatial arrangement and visual properties of elements within a document to infer meaningful structural relationships between them. In accessibility contexts, vis…