Visual substitution

Visual substitution is a design strategy in assistive technology that replaces visual information with output in another sensory modality, such as audio descriptions, haptic feedback, or tactile representations. It contrasts with visual enhancement, which amplifies or augments residual vision. Most assistive technologies for blind and low-vision users employ visual substitution — for example, screen readers convert visual interfaces to speech, and tactile graphics translate images into raised surfaces. Research has shown a strong preference for substitution-based approaches, though this means that solutions for people with low vision who could benefit from visual enhancement are comparatively underexplored.