Stereopsis testing measures fine depth perception arising from small differences in image position between the two eyes. It evaluates the binocular function that enables three-dimensional vision.
Test Types
Common tests present pairs of images that appear displaced in depth when viewed through special glasses, such as polarised or red-green filters. The smallest disparity at which depth can be detected is recorded as the stereoacuity threshold.
- Examples include Titmus, Randot, and TNO stereo tests
- Requires reasonably good vision in each eye and proper alignment
- Children may identify shapes, animals, or circles appearing raised
- Testing is usually performed at near distance; some tests assess distance stereopsis
Clinical Significance
Good stereopsis indicates well-coordinated binocular vision, while reduced or absent stereopsis suggests strabismus, amblyopia, or significant anisometropia. Results inform management decisions in paediatric and adult binocular vision care.
- Helps judge outcomes of strabismus surgery or amblyopia treatment
- Important in occupational assessments for tasks needing fine depth judgement
- Baseline and follow-up tests show changes over time
- Interpreted along with alignment measurements and visual acuity
