suppression scotoma
Also called suppression area, fixation point scotoma, central suppression scotoma, foveal suppression scotoma, zero-point scotoma
A suppression scotoma is the region of one eye's visual field that the brain switches off during binocular viewing to prevent double vision and confusion. The scotoma disappears as soon as the other eye is covered, because there is nothing left to suppress.1,4
In strabismus a central scotoma removes the confusing foveal image, and a peripheral scotoma at the projection of the fixation point removes the double image.1,2,3 The shape follows the deviation: the scotoma falls on nasal retina in esotropia and covers a larger temporal area in exotropia.1,2,3
Suppression differs from amblyopia, which is a loss of acuity that persists with the other eye covered. Constant suppression of one eye can lead to amblyopia, while suppression that alternates between the eyes usually does not.2 The Worth four dot test shows whether suppression is present and how large the scotoma is, and the 4 prism diopter base-out test finds the small central scotoma of monofixation syndrome and microtropia.5
More detail
Facultative suppression appears only while the eyes are misaligned, as in intermittent exotropia, and obligatory suppression is present whether the eyes are straight or not.2,4 A suppression scotoma differs from a scotoma caused by retinal or nerve disease, which is present with one eye alone. Suppression can persist after the eyes are realigned by surgery or glasses, and that persistence is one reason stereopsis may not return.3 Moving the Worth four dot light farther away shrinks the target and shows how large the scotoma is.
Sources (5)
- von Noorden and Campos, Binocular Vision and Ocular Motility, ch. 13
- Kanski, Clinical Ophthalmology (2024), ch. 18
- Yanoff and Duker, Ophthalmology (2023), ch. 11
- Pickwell's Binocular Vision Anomalies, glossary
- Carlson and Kurtz, Clinical Procedures for Ocular Examination, ch. 4
Reviewed October 2026