Plastic eyeglass frames are lightweight and come in a range of colors. The frames are usually made from zylonite, cellulose acetate or nylon, according to the All About Vision website. Most plastic frames can be bent to modify the fit and are easy to adjust when done properly. However, plastic frames can break and become brittle with age. Knowing a few things in advance helps you safely adjust and bend plastic frames.
Check for any damage to the frames, especially the parts of the frames that you are going to bend. Look closely for fine cracks or discoloration. If the frames show any sign of being broken, do not attempt to reshape them.
Warm the frames. Plastic frames must be heated before they can be bent. Fill a sink or bowl with water heated to a temperature your skin can tolerate. Place the frames in the hot water for at least 20 seconds. You can also hold the part of the frames you are bending under a stream of warm running water.
Bend the temple portion, the part of the frames that rest over each ear. Grasp the frames firmly with both hands. Gently bend the curve of the temple over your index finger. Work in small, subtle movements, reheating the frames as necessary.
Bend the temples up gently if they are rubbing the back of your ears and bend them down if your glasses are sliding down your nose. Straighten the entire temple and re-bend the curve to tighten the fit around your ear if your glasses are slipping down all of the time.
Tighten your plastic frames by bending them slightly in the middle. Heat the frames, and then hold your frames so that the front of the lenses are facing away from you. Use the thumbs on both hands to grip the center, inside of the frame. Pull in the outer edges of the front toward you with your fingers.
Loosen the frames. Heat the frames, and then hold them so the lenses face toward you. Curve the frames out by pushing in on the center and pulling the outer edges toward you.
You can use a hair dryer to heat plastic frames to make them warm enough to bend. Hold the hair dryer at least 10 inches from the frames and move the warm, blowing air over the frames for at least 20 seconds.