Contact lenses are small, optical discs that are typically used to improve vision problems (like nearsightedness, farsightedness, presbyopia and, in some cases, astigmatism). Although users tend to refer to them as being placed on the eye, the lenses actually float over the eye on top of the tear film.
There are two main types of contact lenses: soft and oxygen permeable. Soft contact lenses are made of special polymer that holds water, making them soft, pliable and permeable for oxygen to pass through the lens to the eye. They are the most popular kind of contact lens. Oxygen permeable contact lenses are made of a rigid polymer. Because they are hard, they are less comfortable and it takes some time for a new user to adapt to wearing them.
According to the American Optometric Association, more than 30 million Americans wear contact lenses. Two-thirds of contact users are female. Roughly 10 percent of contact wearers are under 18.
Caring for Contacts
New York City Ophthalmologist Hilla Steinberg, M.D., says people who wear contact lenses must be committed to taking proper care of them. Dirty or contaminated contacts can harbor bacteria that get into the eye, causing potentially serious (and sometimes vision-robbing) eye infections.
Here are some general care tips:
Wash your hands before handling your contacts. Steinberg says bacteria on your hands can be transferred to your contacts. The bacteria can then get into the eye.
Clean your contacts. Debris and deposits on the eye can adhere to contact lenses, interfering with vision, causing irritation or discomfort and/or changing the tear film on the surface of the cornea. Thus, it’s important to clean the lenses as directed by your vision care provider or the lens manufacturer. Many experts still recommend rubbing the lens slightly with the contact lens solution to remove the debris and deposits. An alternative to rubbing is to rinse the lens for five seconds on each side with a disinfecting solution.
Clean your case. Bacteria can get inside the case and contaminate the lenses. Case cleaning should be done daily.
Use the right solution. Researchers estimate about 90 percent of contact lens wearers use a multipurpose solution. These products contain ingredients that simplify contact lens care, combining cleaning, rinsing, disinfecting, enzyme cleaning and lubrication in one step. There are many different brands to choose from. If one brand causes irritation, stop using it and try a different brand. Most importantly, DO NOT use water, saliva or a homemade solution to clean your contacts. None of these will disinfect the lenses and you could end up with a nasty eye infection. Steinberg also recommends discarding lens solution that has past its expiration date by more than a month or two because older solutions may lose some of their ability to properly disinfect the lenses.
Replace as recommended. There are different kinds of soft contact lenses. Daily wear contacts are meant to be worn for a day and then discarded when removed. Steinberg recommends these for younger patients and those who don’t want to be bothered with cleaning and disinfecting. Some contacts can used for a week or two (though removed and cleaned every evening), then tossed. Continuous wear contacts are generally worn for up to 30 days before they are discarded. Don’t wear contacts for longer periods than recommended.
Give your eyes a break. The eyes need oxygen. Contact lenses, though somewhat permeable, reduce the levels of oxygen to the cornea. Steinberg recommends giving your eyes two to three hours of non-contact time before going to sleep. She also recommends removing the contacts and wearing glasses when you have a cold or if the eyes become red, irritated or itchy. It’s important to have a pair of prescription eyeglasses handy to use for when you are not able to wear your contacts.
Steinberg has her new contact lens patients sign a contract that states the users understand how to properly care for their lenses and are willing to follow the care guidelines. She cautions contact lens wearers should call their vision care provider if the lenses become uncomfortable to wear or they develop sudden blurred vision, persistent red or irritated eyes or eye pain. If an infection is present, it is more easily treated when caught early.
AUDIENCE INQUIRYIf you have specific questions or concerns about contact lens wear and care, contact your vision care professional. For general information:
American Optometric Association, http://www.aoa.org/contact-lenses.xml
Contact Lens Council, http://www.mycontactlenses.org/foryou.php
BIBLIOGRAPHYCronin, Brenden, “The Red Eye in Contact Lens Wearers,” Australian Family Physician, October 2007, Vol. 38, No. 10, pp. 831-832.
Koffler, Bruce, M.D., and Paul Karpecki, O.D., “Positive Aspects of the Use of Multipurpose Disinfection Solutions,” Archives of Ophthalmology, November 2009, Vol. 11, pp. 1540-1543.
Luensmann, Doerte, et al., “The Efficiency of Contact Lens Care Regimens on Protein Removal from Hydrogel and Silicone Hydrogel Lenses,” Molecular Visions, January 20, 2010, Vol. 16, pp. 79-92.
Pucker, Andrew, and Jason Nichols, O.D., Ph.D., “Impact of a Rinse Step on Protein Removal from Silicone Hydrogel Contact Lenses,” Optometry and Vision Science, August 2008, Vol. 86, No. 8, pp. 943-947.
Szczotka-Flynn, Loretta, O.D., et al., “Risk Factors for Contact Lens Bacterial Contamination during Continuous Wear,” Optometry and Vision Science, November 2009, Vol. 86, No. 11, pp. 1216-1226.