POLYOPIA AND MONOCULAR DIPLOPIA OF CEREBRAL ORIGIN

Abstract

Polyopia, or the seeing of multiple images on focusing on one object, is a relatively uncommon condition. This optical illusion is allied to that of monocular diplopia, or the seeing of two images with one eye. Although these symptoms may be found with hysteria, there are many and varied organic conditions which can produce formation of multiple images.¹Diseases of the ocular media are known to produce monocular diplopia or even polyopia. Here the explanation involves a simple consideration of the physics of light and optics.²The same illusion can be reproduced in the normal subject merely by placing an appropriate lens or prism before the intact eye. Another seemingly peripheral cause of monocular diplopia is strabismus, with resultant reduction in visual acuity. Bielschowsky³described the case of a man who had convergent strabismus and amblyopia in the left eye. The patient lost his normal, right eye,