Contact Lenses: The Next Generation

By Madeline Drexler

Bifocals, multifocals, even corrections for astigmatism — with today's contact lenses, you may never need glasses again.

First you wonder when they started printing menus in such tiny type. Then it's your computer: Did somebody fiddle with the display size? And what's with maps?

Welcome to presbyopia, the midlife vision change that makes it hard to read small print up close or focus on near objects. If you've never needed glasses, it may be time for your first pair. If you've been using contacts for distance, you may have to pop on reading glasses when you want to, well, read. And if you've been wearing glasses for distance, you may need to switch to bifocals or progressive lenses (which correct at multiple distances).

Or maybe not. Breakthroughs in contact lens technology are coming so fast that even if you tried contacts in the past and they didn't work for you, they're worth trying again. "There are more choices than ever," says Thomas Steinemann, M.D., associate professor of ophthalmology at Case Western Reserve University School of Medicine.

LENSES THAT BREATHE

If you ever gave up on contacts because they were too uncomfortable (as one-third or more patients do), consider lenses made of silicone hydrogel, a permeable plastic that allows six to seven times more oxygen to reach the cornea than regular soft lenses do. This not only makes them more comfortable, it also minimizes the problems that plague wearers of other contacts: redness, dryness, swelling of the cornea, and corneal infections. Roughly half of the contacts being fitted today are made of silicone hydrogel. (Note: These are slightly stiffer than regular lenses, so you might need a little time to get used to them.)

The FDA has approved some silicone hydrogel contact lenses for up to 30 days and nights of continuous wear. Even during such a long stretch, they're as safe as the soft seven-day lenses worn continuously: With either, you have a 1 in 2,500 chance of developing an infection that harms vision. Any infections that do arise with silicone hydrogel are generally less aggressive and more treatable.

You can bring down that 1 in 2,500 figure even more by removing your lenses before bed. Leaving any kind of soft lens in overnight increases your chance of infection — up to seven times. Just because silicone hydrogel lenses are approved for continuous use doesn't mean it's the best thing to do. "Do I encourage people to sleep in these lenses? The answer is no," says Dr. Steinemann.

LENSES FOR NEAR, FAR, AND IN-BETWEEN

Bifocals correct both up-close and distance vision. In the past, many wearers complained that these lenses didn't do either well enough. New bifocal lens designs work better, says Louise Schlafani, chair of the Contact Lens and Cornea Section of the American Opto­metric Association. Some models alternate near/distant/near/distant in concentric rings from top to bottom. Others provide distance correction in the center of one eye, with near correction in an outer ring; the other lens reverses the setup.