Diabetic retinopathy is the main cause of blindness in adults 25-74 years of age in Western countries. At 100% diagnosability and 100% treatability, with laser photocoagulation vision can be retained in at least one eye in 73% of patients with proliferative retinopathy and in 67% of patients with diabetic maculopathy. The cost-benefit analysis draws a comparison of the costs incurred through benefits granted to a blind diabetic and those incurred through proper screening, examination and treatment to avoid blindness as much as possible. These calculations are valid for the State of Tyrol in Austria. The anticipated annual costs for blindness are thus ATS 19,000,000, of which ATS 14,600,000 could be avoided through an optimal screening, examination and therapy program. The maximum costs for examination and therapy amount to ATS 10,700,000, thus giving a minimum saving of ATS 3,900,000 in favor of preventive medicine.