
Sunglasses use small screws to hold the top and bottom portions of the frames firmly around the lens. Small screws are also used to join components together on the frames. These screws can loosen over time and should periodically be tightened. Because of small screw sizes, you’ll need a screwdriver with a small blade. Small screwdriver kits are available at most eyeglass stores or pharmacies. A magnifying glass will also be helpful during the repair.
Another trick for keeping screws tight is to use clear nail polish to keep screws from coming loose. Apply the nail polish to the entire screw before you tighten it, then dab a little on the top and bottom of the screw once it is in place. The nail polish is much gentler on your glasses than abrasive super glue, but it will still keep the screw from coming loose or popping out.
If you feel uncomfortable making these adjustments yourself, most eyeglass or sunglass stores will perform this repair as a courtesy to customers.