Similar to clothing, eyeglasses are available in many different sizes. At your first eye exam for eyeglasses, your optometrist will measure your face and the distance between your eyes to find your appropriate eyeglass size. While your prescription will likely change throughout the years, it is less likely that your eyeglass size will change. Once you know your size, you may order eyeglasses to fit your measurements
•1 Find your size. Look for three numbers on the inside arms of your current eyeglasses. Many prescription eyeglasses will have your exact measurements engraved on the arm. If your measurements are not engraved on the glasses, check your paper prescription or contact your optometrist. They should have your information on file.
•2 Select your eyeglasses. Visit a physical store or shop online to find a frame style that suits you.
•3 Provide the measurements for your eyeglasses. The first number is the horizontal width of your eyeglasses in millimeters. The second number in your prescription is the distance between the two lenses, also known as your bridge size. The third number is for the length of the arms of your eyeglasses, also known as temple length.