Convergence Micropsia

Convergence micropsia is a type of micropsia characterized by the reduction in apparent size of objects viewed when the eyes are more converged than they need to be for the distance of the object from the eyes.

It occurs mainly during stereoscopy and when viewing autostereograms (such as Magic Eye pictures). In these cases, the object is depicted by the two half images of a stereogram or by the contents of the autostereogram. Moving the stereogram or the autostereogram closer to the eyes increases convergence of the eyes and reduces the apparent size of the depicted object. If a correctly arranged stereogram or autostereogram is viewed with crossed eyes, then the depicted objects will appear smaller than if it is viewed with eyes diverged or parallel.

Convergence micropsia could also occur if one looked at the world through base-out prisms.