Simulated images of intraocular lens negative dysphotopsia and visual phenomena

Simulated images were generated using an extended source to illustrate peripheral dark shadows in pseudophakic eye models. The shadows are a consequence of the intraocular lens being much smaller than the natural crystalline lens, which limits the extent of the focused image. Compensation is made for the cosine intensity falloff due to pupil obliquity, and the images are envisaged as being displayed on polar plots of visual angle corresponding to approximate retinal locations. Additional retinal illumination from light missing the lens reduces the shadow effect as the pupil diameter increases, in agreement with clinical observations. Lenses with two different cross-sectional profiles were evaluated, which both have shadows at about 85°, but with different characteristics. The iris thickness was found to affect the shadows by occluding peripheral rays. Images were also generated for a point source with a 5 mm pupil, where a double image is created for visual angles as low as 50°, which may contribute to visual phenomena at night. This type of modeling may help with patient evaluations and discussions.