StereopsisTests

StereopsisTests are a group of clinical tools used to evaluate stereopsis, the ability to perceive depth based on binocular disparity between the images seen by the two eyes. These tests help assess binocular vision and detect disorders such as strabismus and amblyopia, and they are used to monitor treatment outcomes and to screen children for vision problems.

Stereopsis tests rely on presenting different visual information to each eye while controlling for or removing other depth cues. Common approaches include anaglyph or polarized displays that separate images by color or light polarization, and random-dot stereograms that contain disparity cues without familiar shapes. Some tests also use real objects or dynamic stimuli to gauge depth perception in more natural conditions.

Prominent examples include the Titmus Fly Test, Randot series, and the TNO test. The Titmus test often uses a recognizable figure or shapes with stereoscopic disparity; Randot tests present random-dot patterns with selectable disparities to measure stereoacuity; the TNO test uses random-dot patterns viewed with colored filters. In modern practice, computer-based or tablet-based stereopsis assessments are increasingly used, sometimes combining multiple modalities in one session.

Interpretation of results is expressed as stereoacuity, typically noted as the smallest detectable disparity (lower values indicate better depth perception). Normative data vary with age and testing method. Limitations include reliance on patient cooperation and the influence of spectacle correction, lighting, and motion; some tests may fail to detect certain binocular issues such as suppression.

Clinical use: Screening, diagnosis, and monitoring of binocular vision anomalies in children and adults; guiding therapy decisions and documenting progression.