Maui Jim plastic sunglasses are made from either cellulose acetate, grilamid, nylon or nylon blends, all of which are moldable high-grade plastics. When heated, these materials can be adjusted or molded with your hands. Although Maui Jim recommends that adjustments be made by a local optician or Maui Jim dealer, you can make some simple adjustments at home to customize the fit of your sunglasses and to make them more comfortable.

Fill a large bowl with hot (not boiling) water. Run your Maui Jim frames through the hot water, swishing them back and forth for about two to five minutes to make the plastic slightly pliable.

Adjust the width of the frame by molding it with your hands, making the temples comfortably rest on the side of your head. To bring the temples closer to your head, press inward on both corners of the frame front, curving the front of the frame slightly. To move the temples farther away from your head, put your thumbs on the inner corners of the hinges and press firmly outward, flattening the frame front slightly and forcing the temples out.

Adjust the frame behind your ears by molding the temples to fit closely into the crotch of your ear (where the top of your ear meets your head). Put on the sunglasses, and make a small mark on the temple with a dry-erase marker where the temple hits the crotch of your ear. Using this mark as the starting point, curve the temple downward with your hands in a gentle slope, pressing the ends of the temples slightly inward so they rest on but do not press against the side of your head.

Straighten the frame, first making note of which side of the frame is higher on your face. Bend the temple of the lower side farther down from where the frame rests in the crotch of the ear. Applying careful pressure where the hinge connects the temple to the frame front, press down to lower the position of the temple, repeating if necessary.

Hold the frames under cool, running water for at least 30 seconds to set the plastic, keeping the customized fit in place.