stereotest

A stereotest is a clinical assessment used to measure stereopsis, the ability to perceive depth based on binocular disparity between the eyes. It is a key component of evaluating binocular vision and is commonly employed in ophthalmology and optometry to detect conditions such as strabismus and amblyopia, as well as to guide treatment decisions and monitor therapy outcomes.

Tests typically present two slightly different images to each eye using specialized eyewear or devices, so that when fused, the viewer perceives a three-dimensional or depth-enabled image. Performance is often expressed as stereoacuity, usually in arcseconds. Broadly, stereotests fall into two categories: contour or shape tests, which provide depth cues from outlines or familiar shapes (for example, drawings or figures), and random-dot stereograms, which contain no recognizable contours and require true binocular disparity to perceive depth.

Common examples include contour-based tests like the Titmus stereo test and various Randot or comparable tests, as well as random-dot stereotests that assess finer depth perception without relying on contour cues. Tests can be administered at near or distance and may use polarized filters, red-green anaglyph glasses, or other viewing methods.

Interpretation centers on whether the patient demonstrates usable stereoacuity. Normal results indicate intact binocular depth perception, while reduced stereoacuity can signal binocular dysfunction such as amblyopia or strabismus. Limitations include reliance on patient cooperation, the influence of monocular cues in some tests, and the effect of visual media and glasses on accuracy.