How to take care of your eyeglasses

Prescription eyeglasses can cost as much as $1,000, and most have plastic lenses, which scratch more easily than glass. Clearly, you need to protect your investment. But should you clean lenses with tissues or cloth? When they're wet or dry? Industry insiders put things into focus for us.

If you're in the market for a new pair of glasses, use our buying guide to eyeglass stores.

• Don't wipe lenses when they're dry. Any debris on their surface or dust in the cleaning cloth could cause scratches.
• Don't wipe lenses with a tissue, paper towel, or paper napkin. They can have a rough surface.
• Don't use ammonia, bleach, vinegar, or window cleaner, which can harm lenses and their coatings. (Most lenses are now coated, usually with an anti-reflective layer.)
• Don't spit on your lens. While spit is a handy cleaning solution, "saliva may contain oil or something else that's damaging," says American Optometric Association spokeswoman Susan Thomas. Exhaling on lenses before cleaning doesn't get them very wet, and the association doesn't recommend it.
• Don't put unprotected glasses in a purse, pocket, or bag.
• Don't regularly place glasses on a sink or vanity top. Spatter, sprays, and cosmetics can soil lenses, and hair spray or perfume can damage anti-reflective coating.
• Don't leave glasses in a hot car. "Especially avoid the top of the dashboard," Thomas advises. "The windshield will act like a magnifying lens."
  

• Do clean lenses regularly with warm water and a drop of dish detergent, then dry with a clean, soft cotton cloth, like a handkerchief, or a microfiber cloth. Launder any cloth routinely according to the manufacturer's instructions. LensCrafters and Pearle Vision, optical retailers that are part of the same company, suggest using an eyeglass cleaner sold at their stores for about $2.50 per 2 ounces. A small bottle of lens cleaner is convenient when you're out and about, but is it better? "Most work very well, but there's no great advantage over liquid soap," says Lee Duffner, an ophthalmologist in Hollywood, Fla., and a spokesman for the American Academy of Ophthalmology.
• Do use a hard-shell case that is the right size for your glasses.
• Do lay glasses down with their lenses facing upward.
• Do use both hands to put glasses on and take them off, and keep glasses on your nose, not on your head. Otherwise, frames can become misaligned. Even clean lenses are less than effective if they aren't positioned properly in front of the eyes.