Can disposable contacts harm my eyes?

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 US Food and Drug Administration, which must approve contact lenses for marketing, believes all these devices are safe and effective if used according to manufacturers’ instructions, a spokeswoman said.