The most common type of cataract is age-related cataract, also known as senile cataract. It can be classified as cortical, nuclear and posterior subcapsular depending on the location of the clouding, and these types can occur separately or together. The clinical manifestations of senile cataracts include loss of vision, blurred vision, myopia and mosquitoes, which can be seen as a fixed black spot in front of the eyes, as well as diplopia or hyperopia, double vision and double vision in one eye. For children, young and strong men and soldiers and other people who work outside for a long time, they are prone to traumatic cataract. Diabetic patients are prone to develop metabolic cataracts, etc.