Contacts are not always the perfect alternative to glasses

Dr. Steven Binder, an optometrist at the Stanford Eye Center, said that "there is an increased risk for infection to the cornea and conjunctiva" in contact lens wearers.

The cornea is the outermost layer of the eye, where the contact lenses are placed. The conjunctiva is the clear tissue surrounding the cornea that covers the surface of the eye.

Binder said he has seen a variety of eye problems related to contact lenses, including "allergies due to protein and lipid build-up to the surface of the contact lens."

Generally, contact lens wearers should watch out for discomfort, blurred vision, redness in the eye, itchiness, puffy eyelids, pain, drainage of a sticky discharge and sensitivity to light as symptoms of contact lens problems.

These symptoms of eye irritation may occur from using contact lenses longer than prescribed and from failing to clean contacts thoroughly. To avoid damage to the cornea and to prevent eye injuries, the Health Scout Network, a provider of consumer health information, said optometrists strongly recommend that individuals always clean their hands thoroughly before touching the contacts. In addition, prevention of such symptoms includes:

1. Washing contact containers and other objects that contacts might touch well.

2. Making sure to follow instructions for the contact lenses. If they are once-a-day disposable lenses, you must discard them each night and use new lenses the next day.

3. Only using commercial solutions, as opposed to homemade contact solutions.

4. Putting on eye makeup after putting in contact lenses.

5. Having your contact lenses checked by a professional each year.

Despite up-to-date contact lens cleansing treatments and precautions, people still face a greater risk for wearing contact lenses that is sometimes unavoidable.

People who are inattentive to cleaning procedures or who absentmindedly fall asleep while wearing contacts face the danger of infection.

Binder said that sleeping with contacts restricts oxygen flow to the eye. As a result, the cornea swells and bacteria can more readily penetrate the corneal surface, also called the epithelium.

Extended contact-lens wear increases the probability of serious infections such as bacterial keratitis. Bacterial keratitis is the most common type of infectious keratitis and people who obtain keratitis can suffer from photophobia and acute pain. Medical treatment, which varies for each patient, should be immediate because keratitis can result in the formation of scar tissue in the cornea that can lead to blindness.

Researchers are working on new technology to improve contact lenses for those who have sensitive eyes and reduce general adverse side effects.

A yearlong study directed by Dr. Philip B. Morgan, an optometrist at the University of Manchester in England, found that eye patients wearing new contact lenses made of silicon hydrogel were less likely to suffer from an eye infection than patients wearing regular contact lenses.

The silicon hydrogel allows oxygen to pass through to the cornea, reducing the risk of eye injuries. Even though these contact lenses were found to be safer, Binder said he still recommended removing contact lenses before sleeping.