To avoid unnecessary facial pain and headaches, proper eyeglass fit is essential. The top of the eyeglass frame should line up with your eyebrows, the frame should be comfortable with no pinching or pulling and should stay on your face without sliding down your nose. If your eyeglasses don't fit like this, you can adjust them yourself by tweaking the eyeglass arms at the temples where they meet the rest of the frame.
Warm the plastic frames up by running the temples under hot water for 20 seconds. Directing a hair dryer on the frames for 20 seconds will also work for this. Keep the hair dryer setting on low so the frames don't get too hot.
Adjust the arms at the temple to remedy glasses that slide down your nose or aren't level on a flat surface. Bend each arm up or down where it meets the frame, moving the arms a tiny bit at a time until they are in the correct position. Apply only the minimum amount of force needed to ensure that you don't break the arms. Glasses are designed to be bent to accommodate different facial structures; bending them beyond what is necessary for your face, however, raises the risk of breaking them.
Run the frames under cold water for 20 seconds to set them in the new position.
Use the needle nose pliers to gently pinch the temple corner while you move the frame slightly upward or downward. This will adjust frames that are off-balance. Moving the frame upward or downward will depend on the side that is off-balance.
Bend the arms slightly away from the frame with your hands if your glasses dig into your head or ears. Likewise, bend the arms slightly inward if your glasses fit your head too loosely. These bends should take place in the middle of the arm shaft. Straighten the ear pieces a little with the pliers if they are too curved for your ear. Bend the ear pieces if they are too straight.
Correct glasses that sit too high or too low on your nose by bending the arms at the temples to change the angle of the frame. Bend both arms slightly upward with the pliers to correct frames that sit too high on your nose. Bend the arms slightly downward to remedy frames that sit too low on your nose. Take care not to bend the actual hinge; place the pliers at the part beyond the hinge, where the arm meets the frame.
Plastic frames that fit too loose or too tight should be taken to an eye doctor for the proper adjustments. For the best outcome, any frames that need major or multiple adjustments should be taken to an eye doctor.