title: Double image in far peripheral vision of pseudophakic eye as source of negative dysphotopsia.
abstract: Some intraocular lens (IOL) patients report seeing "dark shadows" at visual angles that are larger than 60°-70°. Raytrace models of the pseudophakic eye show that light starts to miss the IOL at large visual angles because the implant diameter of about 6 mm is much smaller than the natural crystalline lens diameter of 9.5 mm. This light forms a second displaced image on the peripheral retina. To evaluate the appearance of the image, raytrace software was used to image an illuminated window onto the highly curved retina, and a method was developed to project the image back to object space for evaluation on a flat surface. Only a single schematic eye was evaluated monochromatically and the low resolution of the peripheral retina was not modeled, but the simulated images depict a shadow-like phenomenon at similar visual angles to reports of "negative dysphotopsia."
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Simpson
mesh_terms: D004172:Diplopia / Q000150:complications* / Q000503:physiopathology*; D006801:Humans; D019591:Pseudophakia / Q000150:complications*; D012984:Software; D014796:Visual Perception