Meridional size disparity as a function of compressed inferior visual space: a case in point.

This case report describes a very unusual form of aniseikonia which was eventually documented to be variable within the total field of vision and limited to vertical space perception. Initially the condition could be partially relieved by monocular occlusion, visual training procedure, and the use of isoikonic lenses. Ultimately, the greatest improvement was produced by the introduction of prismatic properties to the lenses which directly addressed the patient's problem of meridional space perception.