Even with perfect vision, everyone should get an exam by age 20 and then every few years after that. Get a baseline screening for blinding diseases such as glaucoma by age 40. “You may not realize there’s a problem, but your ophthalmologist can identify subtle changes that indicate eye disease,” says Stephanie Marioneaux, M.D., spokesperson for the American Academy of Ophthalmology. “He or she also can see early signs of other health problems such as hypertension, diabetes or lupus.” If you wear glasses, see your eye doctor at least every two years. For contacts, it’s every year.