An optometrist is a health professional who specializes in examining eyes and prescribing glasses or contact lenses. When you go for an eye exam, you're likely visiting an optometrist. They check how well you can see, test whether you need glasses, and look for signs of eye diseases or problems.

During an eye exam, an optometrist might have you read letters on a chart across the room, look through different lenses while asking, “Which is clearer, one or two?”, and shine lights into your eyes to check their health. If you need glasses, the optometrist writes a prescription specifying exactly how strong the lenses should be to correct your vision.

Optometrists attend four years of optometry school after college. They're different from ophthalmologists, who are medical doctors who can perform eye surgery, and opticians, who help you choose frames and make your glasses based on the optometrist's prescription.

If you're squinting at the board in class or getting headaches while reading, an optometrist can help figure out whether you need glasses.