Glossary

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CCTV Magnifier(also: Closed-Circuit Television Magnifier, Video Magnifier, Desktop Video Magnifier)

An assistive device that uses a camera to capture an image of text or objects and displays it magnified on a screen, typically a television or computer monitor. CCTV magnifiers are one of the most widely used low vision aids, offering high levels of magnification, adjustable…

CVD Simulation(also: Colour Blindness Simulation, Color Vision Simulation)

A technique that transforms colours in a design to approximate how they would appear to a person with a specific type of colour vision deficiency. CVD simulations are the most widely implemented feature in accessibility design tools, available in browsers (Chrome, Firefox),…

Camera Framing(also: Photo Framing, Object Framing)

The act of positioning a camera so that the intended subject is properly captured within the image frame — not cropped, not too small, and centered enough for clear identification. Camera framing presents a significant accessibility challenge for blind and low-vision users who…

Camera Phone(also: Smartphone Camera, Mobile Camera)

A camera phone is a mobile phone equipped with a built-in image sensor, which in an accessibility context serves as the input device for a wide class of vision-based assistive applications. Modern smartphone cameras enable live scene description (Seeing AI, Be My AI), object…

Children with Vision Impairments(also: CVI, Students with Visual Impairments, Blind Students)

Children and young people who are blind or have low vision, requiring adapted educational approaches including Braille instruction, tactile learning materials, audio resources, and assistive technology. India has the world's largest population of children with vision…

Choropleth Map(also: Thematic Map, Shaded Map)

A type of thematic map in which geographic areas are shaded or patterned in proportion to a statistical variable, such as population density, income level, or unemployment rate. Darker or more intense colors typically represent higher values. Choropleth maps are widely used by…

Color Filter(also: Color Filters, Display Color Filter)

An operating-system or browser-level feature that alters how colors are rendered on screen, including grayscale, inverted colors, and filters for protanopia, deuteranopia, and tritanopia color vision deficiencies. Used by low-vision users and users with color vision deficiency…

Color Theory(also: Colour Theory)

A body of principles and guidelines for understanding how colors interact, combine, and affect perception. In accessibility contexts, color theory is important for ensuring sufficient contrast ratios, avoiding color-only information encoding, and designing for color vision…

Color Universal Design(also: CUD, Colour Universal Design)

A set of guidelines and principles developed to ensure that colour use in designs, products, and environments is accessible to people with all types of colour vision, including those with colour vision deficiency. Color Universal Design emphasizes selecting colour palettes that…

Colour Contrast(also: Color Contrast, Contrast Ratio)

The measurable difference in luminance or colour between two adjacent elements, used to determine readability and visual distinguishability. WCAG defines minimum contrast ratios (4.5:1 for normal text, 3:1 for large text at AA level) based on relative luminance calculations…

Colour Palette Generation(also: Color Palette Generation, Accessible Palette Generation)

The automated or semi-automated creation of sets of colours that are distinguishable by people with different types of colour vision deficiency while meeting aesthetic and functional design requirements. Despite its importance, colour palette generation is an underrepresented…

Colour Vision Deficiency(also: CVD, Color Blindness, Colour Blindness)

A condition in which a person has difficulty distinguishing between certain colours due to differences in the cone cells of the retina. CVD affects approximately 1 in 12 men and 1 in 200 women worldwide. It is not typically a complete inability to see colour but rather a reduced…

Colours of Confusion(also: Confusion Colors, Confusable Colours, Metameric Pairs)

Pairs or sets of colours that appear distinct to people with typical colour vision but appear identical or nearly identical to people with a specific type of colour vision deficiency. These colour pairs are predicted by CVD colour models and underlie CVD simulation tools.…

Comic Strip Conversations(also: CSC)

A visual-support technique developed by Carol Gray (1994) for autistic children and adolescents, in which a social interaction is illustrated as a short comic strip with simple stick figures, speech bubbles, thought bubbles, and colour codes for emotion. By externalising who…

Conditional Formatting

Conditional formatting is a spreadsheet feature that automatically applies visual styles — fill color, font color, bold text, icons, data bars — to cells whose values meet specified rules (for example, highlighting failing grades in red or above-average sales in green). It is…

Contrast Ratio(also: Color Contrast Ratio, Luminance Contrast Ratio)

A numerical measure of the difference in perceived brightness between two colors, expressed as a ratio ranging from 1:1 (no contrast) to 21:1 (maximum contrast, black on white). WCAG 2.2 requires a minimum contrast ratio of 4.5:1 for normal text and 3:1 for large text (Level…

Convergence Insufficiency(also: CI)

A binocular vision disorder in which the eyes have difficulty turning inward (converging) to focus on nearby objects, causing symptoms such as double vision, eye strain, headaches, difficulty reading, and blurred vision during close work. Convergence insufficiency affects an…

Crowd Accessibility(also: Crowdsourcing for Accessibility, Human-Powered Access Technology)

An approach that combines human intelligence with machine intelligence to create accessible content and services for people with disabilities. In crowd accessibility, micro-tasks that automated systems cannot yet perform reliably — such as describing images, identifying objects,…

Cursor Locator(also: Pointer Locator, Cursor Finder, Find My Cursor)

A software utility that helps users find the position of their mouse pointer on screen when it has been lost from view. Cursor locators typically activate through a keyboard shortcut or by detecting pointer behavior such as rapid shaking, and then draw attention to the pointer's…

19 results.