Contact Lens Disease

While most contact lens wearers never experience anything more serious than eye irritation or at most mild conjunctivitis, there are some serious conditions and diseases associated with contact lenses that contact lens wearers should be aware of.

The First Contact Lenses

• The earliest contact lenses were made of glass and were extremely impractical and difficult to wear. In the 1950s, the first prescribed contact lenses were introduced. They were made out of hard plastic and were very uncomfortable for the wearer. These lenses were not designed to be worn for extended periods of time. It was not until the 1970s that soft contact lenses were invented, that the idea of wearing contact lenses instead of glasses for vision correction really caught on with the general public.

Types of Contact Lenses

• Today, there are several different types of contact lenses: soft, hard, toric and bifocal. The type of vision problem that a patient has determines which type of lens a doctor will prescribe. Most people are soft contact lens wearers, but bifocal contact lenses are also very common among patients with astigmatism.

Serious Diseases Associated With Contact Lenses

• The most serious types of disease associated with contact lenses include corneal ulcerations and amoebic keratitis. Corneal ulcerations are usually caused by overwear of soft contact lenses and/or poor hygiene and improper cleaning habits. Many people use their saliva or tap water to clean their lenses when no solution is available, and this can lead to the introduction of harmful bacteria onto the lenses, and in turn, into the wearer's eyes. Corneal ulcerations can cause extreme irritation, sensitivity, permanent eye damage, and if left untreated, can lead to blindness.

  Amoebic keratitis is also believed to be caused by improper care of lenses and bad hygiene on the part of the user, as well as prolonged wear. The Acanthamoeba, an organism commonly found in soil and water, is responsible for AK. Once the organism is transferred from the contact lens to the eye, it cannot be killed by commercial contact lens solution and must be treated with doctor-prescribed antibiotics.

Other Diseases and Conditions

• Some soft contact lens wearers can develop a sensitivity to their lenses, which causes eye redness, increased mucus and irritation. Usually, the only solution is to stop wearing contact lenses for a while and then retry with a new type of lens and a new type of cleaning solution. Certain people are sensitive to specific types of lenses and solution and not others, but the main cause of contact lens sensitivity is overwear and over-dryness which is aggravated when the lens rubs against the eye.

  Rigid, or hard contact lens wearers who wear their lenses for extended periods of time are at an increased risk for corneal abrasion. Pain and tearing are the most common symptoms, and it is important to treat these abrasions promptly with antibiotics to avoid developing corneal ulcerations.

Prevention

• The vast majority of contact lens diseases, conditions and irritations are caused by the same three things: overwear, improper cleaning and poor hygiene on the part of the wearer. The U.S. Food and Drug Administration (FDA) has released the following guidelines for handling contact lenses:

  Always wash your hands before and after handling contact lenses to reduce the risk of infection.
  Only use contact lenses and solutions that have been prescribed to you by your doctor and make sure to follow all of your doctor's instructions for care and use.
  Never reuse contact lens solution in your lens case. Always refill with fresh solution to avoid spreading bacteria.
  Do not use any type of water, homemade saline solution or your own saliva to re-wet your contact lenses.
  Visit your eye doctor at the first sign of an eye infection or irritation. Prevention and early detection is the key.