Contact Lenses and Your Corneas

Contact lenses fall into two main categories Rigid gas-permeable lenses (RGPs) tend to provide clearer vision, let more oxygen pass through to the eye, and are particularly useful to correct vision in people whose corneas have an irregular shape. They tend to be more expensive than soft lenses, but last longer. Old-fashioned RGPs sit directly on the cornea, moving each time you blink to let tears get under the lens. Newer scleral gas-permeable lenses are more concave and have a larger diameter; the edge sits on the white part of the eye, vaulting over the cornea, so fluid remains between corneas and contacts.

Soft lenses are meant to be discarded after a period of use, whether daily, biweekly, or monthly. Many people find them more comfortable and more convenient than RGPs, but less helpful if you have significant astigmatism. Though the Food and Drug Administration has approved certain soft lenses for extended (overnight) wear, cornea specialists warn that overnight wear greatly increases the risk of a corneal ulcer infection, which can be quite painful and lead to permanent vision loss./

How Contact Lenses and Your Corneas Interact

Over time, traditional RGPs actually reshape corneas. Scleral lenses do that less, soft lenses even less, but they all can cause some amount of warping of the corneal shape. If you leave lenses out for long periods, corneas go back to their natural shape. It is therefore recommended that patients planning for cataract surgery or LASIK take them out well in advance, so eye doctors can accurately determine the natural shape of the corneas in order to get the best surgical outcome.

Three Things You Should Never Do

1. Don’t sleep with contacts in. A half-hour nap isn’t a big deal. But overnight sleep increases the risk of a corneal ulcer, the number-one reason for corneal transplants. A mild ulcer causes temporary irritation, can be dealt with by antibiotic drops and may leave a small scar. (If you’re lucky, it won’t be in the center of the cornea.) Worse infections leave permanent scars, are very painful and cause permanent vision loss.
2. Don’t wear lenses in the water, whether swimming or showering. Some water-borne bacteria, when combined with contact lens wear, can cause some of the most severe corneal ulcer infections. The change in humidity in a shower can alter the shape of your contacts, making it more likely that they may get stuck on the eye when you try to remove them.
3. Don’t handle contacts without washing your hands first and use recommended fluids --not plain water -- to soak them. If you splash water on your face, close your eyes first. Avoid rubbing your eyes vigorously, which can injure corneas at any time but especially when wearing contacts.

Two Things Contact Lens Wearers Should Regularly Do

1. If any type of lens causes irritation, listen to your body and remove them – and keep eyeglasses handy for backup visual clarity.
2. Go for annual eye exams. During your annual eye exam, your doctor will check both your contact lenses and your corneas to see if you need a new prescription – and, more importantly, whether hidden issues have arisen. Physicians look for a variety of contact lens-related problems such as out-of-place blood vessels that grow into your cornea from excess lens wear, signs of damage to corneal stem cells, or evidence of giant papillary conjunctivitis, inflammation under the eyelids due to protein that builds up on contacts. Doctors sometimes suggest disposable soft lenses for people who secrete more protein in their tear film.

Questions? Schedule an Eye Exam.

To make an appointment for an eye exam at Horizon Eye Care, use our Patient Portal or call 704-365-0555 Monday through Friday between 8 a.m. and 5 p.m.