The effect of technology on the indications for cataract surgery.

Before the introduction of modern ophthalmic surgical technology following World War II, cataract extraction was easier and safer to perform if the cataract was far advanced (mature) and both eyes were involved. The surgeon was constrained from early surgery by the frequency of severe complications, the long convalescent period, and the distortions of aphakic glasses. Now it is easier to perform phacoemulsification and implant lenses in the early stages of cataract formation when the nucleus is soft and the posterior lens capsule has not been weakened with age. Also, modern small-incision extracapsular cataract extraction has a low rate of complications and a short convalescent period. It is feasible to extract a clear lens or one with minimal opacifications and have a grateful patient. The surgeon is capable of improving the refractive state of the eye by selecting the power of the intraocular lens. These facts have led to instances where cataracts have been extracted that were responsible for minimal or no symptoms.