Vision & Blindness

Vision differences cover a wide range, and so do the tools people use. Blind people typically use screen readers, often alongside braille displays. People with low vision use magnification, larger text, higher contrast, and customisable colour schemes. People with colour vision deficiency need information conveyed by more than colour alone. These are distinct experiences, not points on a severity scale.

Three W3C user stories show part of this range. Lakshmi, a senior accountant who is blind, uses a screen reader at work and hits barriers with unlabelled images, form fields without labels, keyboard shortcuts that conflict with the screen reader, and visual CAPTCHAs. Elias, a retired architect with low vision, relies on browser zoom and text-size controls, and is frustrated by text that won't reflow, controls that are too small, and distorted CAPTCHAs. Lexie, an online shopper with colour vision deficiency, regularly hits interfaces that rely on colour alone: required fields marked only in red, charts without labels, apps that tell teams apart only by jersey colour.

Use semantic HTML so screen readers and braille displays can interpret structure correctly. Write meaningful alt text. Let text reflow when resized without horizontal scrolling. Provide generous contrast. Use large, well-spaced controls. Never rely on colour alone, and replace image CAPTCHAs with simpler alternatives.