Glare measurements before and after cataract surgery.

The efficacy of cataract surgery in improving visual performance was evaluated in 10 patients by measuring changes in intraocular light scatter, contrast sensitivity and glare induced visual loss. Two different methods were used to estimate these functions before and after cataract extraction with implantation of a monofocal posterior intraocular lens. By one method intraocular light scattering was assessed. By the other, letter contrast sensitivity and glare induced visual loss were determined. Preoperatively most patients had various glare problems, glare induced visual loss and increased intraocular light scatter. Following surgery the letter contrast sensitivity increased by a factor of 3 or more (mean 4.3). The glare problems diminished or disappeared after surgery, although several patients still had increased intraocular light scattering and glare induced visual loss compared to normals. Postoperatively the contrast sensitivity both with and without glare had increased to a level where the glare induced visual loss did not create any visual problems.