Optometry is the profession of examining people's eyes to check their vision and eye health. An optometrist (someone who practices optometry) tests whether you can see clearly at different distances, checks for eye diseases, and prescribes glasses or contact lenses if you need them.

When you visit an optometrist, you might read letters on a chart across the room, look into special machines that photograph the inside of your eye, or try different lenses while the optometrist asks, “Which is clearer, one or two?” Optometrists can spot problems like nearsightedness (trouble seeing far away) or farsightedness (trouble seeing up close), and they watch for eye diseases like glaucoma.

Optometry is different from ophthalmology, which is the medical specialty where doctors perform eye surgery and treat serious eye diseases. Think of it this way: an optometrist helps most people see better through glasses or contacts, while an ophthalmologist operates on eyes when something more serious needs fixing. Many people visit an optometrist every year or two for a regular eye exam, the same way they visit a dentist for checkups.