Assessment of visual function | Assessment of functional vision | |
---|---|---|
Examples | Visual acuity, visual field, contrast sensitivity, dark adaptation, colour vision | Use of vision to learn orientation and mobility, daily living skills, communication, sustained near activities, and to gain visual access to information |
Measured | Separately for each eye | With both eyes open |
Scale | Based on stimulus characteristics | Based on response characteristics |
Tests | Single variable under controlled, usually static conditions | Multiple variables under real-life conditions |
Criteria | Threshold performance | Sustainable performance |
Involves | Visual parameters only | May also reflect non-visual factors |
Key vision areas | Example of vision-related functions |
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Ocular motor | Fixation, saccades, scanning, accommodation, refraction |
Sensory functions | Visual acuity near and distance, contrast sensitivity, colour vision, visual field |
Early processing | Figure ground, background ground, stereovision, matching colours |
Interior temporal networks | Face recognition, reading words, copying pictures |
Parietal networks | Spatial awareness, body awareness, eye-hand coordination |