A surgeon analyzes his perception following removal of cataracts and repair of a retinal detachment. His conclusions are: aphakic eyes perceive ultraviolet light, the optic disc is perceived as a point rather than a space the size of the disc, a certain minimal similarity of light intensity on the two retinas is necessary for fusion of images, reduction telescopes can be made by a combination of contact lenses and trifocals which balance the image size in unilateral aphakia, the visual angle of cataract glasses may be only 56 degrees but is perceived as 90 degrees with a 22 degrees blind sector, a patient can observe the progress of his own cataract by looking through a pinhole, and the optimal prescription for contact lenses in aphakia is with acute vision provided at 75 cm. rather than at 5 or 6 m.