Stop Smoking
Smoking is very hard on your eyes, not to mention a lot of other body parts.
Smokers are very susceptible to developing cataracts, age-related macular degeneration, glaucoma, and dry eye syndrome. Diabetic smokers increase the chance of getting diabetic retinopathy.
Stopping smoking might not reverse any eye damage, but it will stop it from getting worse. There are a lot of support groups out there and your doctor can help you find other treatments.
What about carrots?