This book represents the first full treatment of age-related cataract, the primary cause of impaired vision in the elderly and the leading source of blindness worldwide. The first part of the volume describes the deterioration of the human lens in unprecedented detail. It also examines the known causes of the disease, which can be accounted for by exposure to heat, oxygen, and especially ultraviolet radiation. These causal factors are evaluated with regard to the extent they are capable of producing the specific cellular and molecular changes which take place during aging and cataract formation. The second part of the text is devoted to a practical proposal for a safe, simple, and inexpensive program to help prevent the occurrence of age-related cataract.