Diabetic, what kind of ways are there to help prevent blindness?

Prevention. (1) control your diabetes: A1c less than 7. (2) control your blood pressure: top number less than 130 / bottom number less than 80. (3) annual eye check.
Routine exams. Diabetic retinopathy can progress without symptoms. Once symptoms occur, there is usually permanent damage. Best way to prevent blindness is to have routine exams, and treat certain stages of retinopathy before permanent damage occurs. Untreated diabetic retinopathy can lead to blindness.