Contact Lenses: The Next Generation
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.
Bifocals take getting used to, as do all lenses that provide correction at different distances. “You need to learn to ignore the part of the image that’s not in focus,” says Dr. Steinemann. “Some people can do it, some can’t.”
Monovision lenses: With these, one lens corrects your dominant eye solely for distance, and the other lens corrects the other eye for near vision. While many people find monovision lenses easier to use than bifocals, you lose some depth perception, which can interfere with driving or playing sports. Also, you don’t get any mid-range correction, needed at the computer. You can opt for an intermediate-distance lens in place of the one for near vision, but then you may have trouble reading small print.
Multifocals give you all three: near, mid-range, and distance correction. While older studies show that only half of patients stayed with multifocals, today some practitioners say the number is closer to 70 percent. You’re a good candidate if you’re just beginning to have trouble with near vision and you regularly use a computer.
Lenses for Special Problems
Toric: Soft contacts were once out of the question if you had astigmatism—blurred vision typically caused by an irregularly shaped cornea. Now there are soft toric lenses, created with varying prescription powers, that correct the problem. Fitting isn’t easy, so look for an experienced eye doctor (and expect to pay more). Some specialists, however, believe that the best torics are still the older rigid gas-permeables. “You get the clearest, most crisp vision,” says Dr. Steinemann.
Moisturizing: Eye dryness is a major challenge for lens wearers — and it gets worse at middle age. Several new contacts come with claims that they minimize dryness (for one brand, CooperVision Proclear, the claim has been approved by the FDA). Anecdotal evidence suggests that moisturizing contacts help somewhat, but haven’t completely solved the problem. Ditto for drops. Formulas are improving, but aren’t totally doing the trick yet either. “The biggest problem we have now is finding a really good rewetting drop,” says Edward Bennett, co-chief of the contact lens service at the University of Missouri–St. Louis College of Optometry.
UV protection: Several companies make contacts that filter out damaging UV rays. They shouldn’t replace sunglasses, however. Contacts cover only the inner circle of the eye surface, not the whites of the eyes; they also don’t protect the eyelids, where sun-related cancers are most likely to crop up.
In May, the FDA issued an alert about Complete MoisturePlus Multi-Purpose Solution. The contact lens product, made by Advanced Medical Optics, had been linked to an unusual number of serious eye infections (Acanthamoeba keratitis), caused by a parasite.
In 2006, a different solution, Bausch & Lomb’s ReNu with MoistureLoc, was linked to a fungal infection. In that case, a reformulation of the solution had inadvertently created an environment in which fungi thrived. But researchers also found that lens wearers who’d been careless about cleaning and replacing solution every day were the ones who got infections. These products have been taken off the market, but you still need to:
Wash hands before putting in or taking out lenses.
Rub your lenses when you clean them; soaking alone doesn’t remove debris.
Clean your lens case daily (with hot water). Let it air-dry, rinse with multipurpose solution, and fill it with a fresh supply. Never top off old solution with new.
Replace your case monthly.
Keep your eyes moist. Use rewetting drops or artificial tears several times a day.