Clean your eyeglasses regularly with a soft handsoap and water. The dirt and grime in between your frames is not just unsightly, it builds up and can cause further damage to the lenses. Use a lens cleaner or some three-in-one oil to protect the plastic lenses and make future scratches easier to remove.
Draw over the scratch with a special marker such as Sandford's White Peel-Off China Marker. The material from the marker gets into the scratch, filling in the microscopic cracks. Buff the surface to a shine with a soft cloth, and they’re good as new. This method works particularly well with smaller scratches.
Apply a CD- or DVD-cleaning solution and follow the directions on the packaging. You’ll apply a spray or solution and then remove the excess. These kits remove larger scratches from your digital discs, and they’ll work on your eyeglass lenses, too. Experiment with an anti-dust spray such as Pledge, or other kinds of household sprays.
Buff the scratch away with a progression of cloths. If you work on it hard enough, a soft chamois cloth can remove the scratch. Don’t use cloths that are too hard, as they could just make the scratch worse or create more.
Bring your glasses to a professional to see if repair work can be done on the lenses. If a scratch is just too big or too unsightly, there may not be much that can be done. A professional should have the last word before you replace the lens.