I use disposable contacts that I change every day. Over the years, am I harming my eyes?
Probably not, but you should have your eyes checked annually to make sure.
There are all sorts of contact lenses on the market -- from rigid, gas-permeable lenses that are relatively stiff and that you change once a year, to soft, very flexible disposables that you change every day, every two weeks, once a month or once every three months.
The Food and Drug Administration, which must approve contact lenses, believes all these devices are safe and effective if used according to manufacturers' instructions, a spokeswoman said.
"Most people can safely wear disposable contact lenses for years. We have some patients in their 90s who have been wearing contacts for decades," said Jill Beyer, an optometrist and clinical director of the contact lens service at the Massachusetts Eye and Ear Infirmary.
Of all the contacts available, "The one-day disposable is the safest," said Elliott Myrowitz, an optometrist at the Wilmer Eye Institute at the Johns Hopkins University. That's because you are putting in a fresh, sterile lens every day, he said, thus minimizing the risk of infection and the buildup of proteins from tears on the lens.
Other disposables are OK, too, as long as you soak the lenses in the solution that your optometrist suggests to "kill any bugs round the lens," said Lawrence Phillips, an optometrist at For Eyes in Cambridge, Mass. It's also important, Phillips said, to make sure lenses are fitted to the exact curvature of the eye: "A contact lens is not something that you just take off the shelf and put on. It has to be fitted and monitored."
In general, optometrists say, contact lens wearers should be on the alert for three possible warning signs: eyes that feel dry or gritty, eyes that look red or irritated, and vision that is not clear with contacts in place.
"Very few people have these complications if they come in for an annual eye check and follow the correct hygiene procedures," Beyer said.
With Chief Justice William H. Rehnquist battling thyroid cancer, I'm wondering: Is thyroid cancer on the rise in the United States? If so, is it due to Chernobyl?
Cancer of the thyroid, a butterfly-shaped gland in the neck that secretes hormones, is on the rise here: It's expected to strike 23,600 Americans this year and kill 1,460, said Dr. Michael Thun, who heads epidemiological research for the American Cancer Society in Atlanta. Most of the increase is due to better detection, because of CT or ultrasound imaging that can find small tumors that would have been missed in the past.
In its most common forms, the survival rate with thyroid cancer is 85 percent among patients 40 to 50 years old, said Dr. Marshall Posner, medical director of the head and neck oncology program at Dana-Farber Cancer Institute.
Anaplastic thyroid cancer, the type Rehnquist is believed to have, is rare but far more deadly, typically killing victims in three to six months.
As for Chernobyl, despite some data studies suggesting a possible link, a connection appears unlikely. In the 1986 Ukrainian accident, large quantities of radioactive iodine were spewed from the nuclear reactor onto the ground, where cows ate contaminated grass and produced contaminated milk, said Elaine Ron, a senior investigator in the radiation epidemiology branch of the National Cancer Institute (NCI) in Bethesda.
Radioactive iodine is absorbed by the thyroid gland, where it can cause cancer. Researchers have documented a sharp increase in thyroid cancer in people who were younger than 18 and lived near Chernobyl at the time of the accident.
In the United States, radioactive fallout occurred in parts of the West after nuclear weapons testing in the 1950s, but there has been no proof of a link to an increased risk of thyroid cancer, according to the NCI. There is a link, however, between receiving radiation to the head and neck as a child and subsequent thyroid cancer.
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