What is the phenomenon in which the type of correspondence shifts depending on which eye is fixating?

• A. Co-variance
• B. Covariance
• C. Co-variation
• D. Variation

Answer: (A)

Retinal correspondence can adapt depending on which eye is used to fixate. In binocular vision, the brain usually maps a point in one retina to a corresponding point in the other to fuse images. But when fixation switches from one eye to the other, the specific retinal points that are treated as corresponding can change. This linked change in how the two retinas correspond as fixation eye changes is called co-variance. It reflects the brain’s flexible strategy to preserve single, fused vision across different fixation conditions, and it’s a concept that helps explain how alternating fixation and related phenomena can occur.