Your eye doctor measures your visual acuity to see if you need glasses or contact lenses to improve your vision. You'll be given a numbing drop in your eyes. Then your eye pressure is measured. To make it easier for your doctor to examine the inside of your eye, he or she will likely dilate your eyes with eyedrops.

Most eye care professionals recommend that you have a comprehensive eye exam every one to two years, depending on your age, risk factors and whether you currently wear eyeglasses or contact lenses. Children need regular eye exams to detect vision problems that may interfere with learning.

Since your eye doctor will examine your eyes for signs of medical issues, such as high blood pressure, it's best to avoid anything that can raise it. Having caffeine before your eye exam can make your blood pressure look more elevated than usual, which can affect your eye examination test results.