Contact Lens Problems

Contact lenses are small plastic discs that float on a film of tears and sit on top of the cornea, the clear outer layer of the eyeball that covers the pupil and iris. They are an alternative to eyeglasses or laser surgery to correct refractive errors such as nearsightedness (myopia), farsightedness (hyperopia), astigmatism (an irregularly shaped cornea that causes blurry vision) and presbyopia (age-related changes in the lens of the eye). 

Contact lenses should not be worn if you have had a viral infection of the cornea, if you are unable to insert and properly clean the lenses, if you have problems blinking or you have “dry eyes,” eyes that don’t produce enough lubricating tears.

Contact lenses offer several advantages: There are no eyeglass frames to interfere with side vision or activities such as sports; the lenses move as your eye moves so your normal field of vision is not changed; and they do not become spotted or fog up, like glasses. Contact lenses are seen by many as a cosmetic improvement over eyeglasses.

There are disadvantages, however: They require much more attention to cleanliness and hygiene than do glasses; scratches, injury and infection are more common with contacts, and while these injuries are healing, you cannot wear the lenses; allergy sufferers may have difficulty with contacts; and although multi-focal contacts are available, they provide unsatisfactory results for most people with presbyopia who require bifocal or trifocal lenses. In addition, most contacts are now disposable, with a limited lifetime. They represent an ongoing purchase with the additional expense of cleaning fluids and storage containers. Finally, for people with previously normal vision who develop presbyopia, an inexpensive alternative to prescription contacts lenses exists: over-the-counter reading glasses, which are universally available.

Contacts lenses come in two basic types: soft contact lenses made of flexible plastic and water that mold to the shape of the cornea, and rigid lenses, which are made from silicone and are slightly flexible. Both types allow oxygen to pass to the cornea.

You should keep these factors in mind: the comfort of the lenses, your willingness to care for them and their cost. Soft contact lenses may be more comfortable to insert and usually take only a few days to become accustomed to. Because many soft lenses are disposable, there is less chance of getting an eye infection and less cleaning is required. Soft lenses, however, can absorb bacteria and other infecting organisms and substances that can irritate your eyes, such as soap from your hands. They are more easily torn. Rigid gas permeable contact lenses (RGPs) are more durable; resist buildup of deposits, making them easier to clean; and usually give clearer vision. It may take several weeks to become accustomed to wearing them, however. They must be worn consistently, they can slip off the eye more easily than soft lenses, and particles that irritate the cornea can get underneath the lens. A lens that combines advantages of both, called a hybrid lens, is available. This contact lens has a slightly flexible plastic center and a soft plastic outer ring. It gives the clearer vision of an RPG and the comfort of a soft lens.

Soft contact lenses come in several variations: daily-wear, which must be removed and cleaned each night; daily-wear disposable, which are worn for one day then discarded; extended-wear, which can be worn continuously without removal for sleep for up to seven days; extended-wear disposable, which can be worn continuously for one to six days, then discarded; and planned replacement lenses, which are daily-wear lenses that are replaced at a specific period of time, such as weekly or monthly.

RPG lenses are available in daily-wear and extended-wear types.

Potential Problems

Wearing contact lenses puts you at more risk for eye infections; corneal abrasions, or injuries to the cornea; and corneal ulcers, or open sores in the outer layer of the cornea usually caused by infection.

Problems with contact lenses are most often caused by wearing them for too long, eye dryness, grit, allergy, damage to the cornea and infection.

Infections of the cornea can be caused by wearing contacts while sleeping, improper cleaning or using saliva to moisten contacts. Wearing lenses overnight increases your risk for infection because they reduce the amount of oxygen that gets to the cornea. Too little oxygen to the cornea can stress or damage its surface, which makes it more susceptible to infections from viruses, bacteria or fungi. Infection with a microscopic parasite can occur if you wear contact lenses while swimming in pools, lakes or ocean; if lenses are stored in a homemade solution, or if you have poor lens hygiene.

Allergies to pollen can become worse when wearing contacts because pollen can stick to contacts. Some people become sensitive to preservatives in contact lens cleaning solutions or to the contacts themselves.

Damage to the cornea can come from scratches by material trapped under the lens or abnormal growth of blood vessels in the cornea if the cornea does not get enough oxygen.

Wearing contacts for too long can make the eyes feel tired, dry and gritty. This is especially true for a new contact lens wearer, but it can affect anyone who has had lenses in for too long. It can make eyes red and generally irritated. Soft contact lenses can dry out while you are wearing them. If they become dry, they can shrink and put pressure on the front of the eye, causing redness, pain or blurred vision.

Dry eyes can be brought on by wearing the lenses for too long, especially if you are susceptible to this condition because of the environment, aging, medications, illness or a general predisposition to dry eyes. Dry climates and forced air heating in a car, home or building can irritate the eyes, especially when contact lenses are worn. Don't wear contacts if you expect to be in a dusty or sandy environment. Some medications also can cause dry eyes.

What to Do

These are symptoms that could mean irritation, infection or another serious condition:

• Pain or discomfort

• Excess tearing or other discharge from one or both eyes

• Unusual sensitivity to light

• Itching, burning or grittiness

• Unusual redness

• Blurred vision

• Swelling

If you have any of these symptoms, contact your eye doctor right away. Remove your lenses but don’t discard them; your doctor may need to examine them to determine the cause of your symptoms.

Always follow your health care provider's advice about how often and how long the lenses should be worn, as well as how to clean and store your contact lenses. Wash your hands with soap and water before touching contact lenses. Insert lenses before applying cosmetics and remove them before removing makeup.

Get an annual contact lens exam, because the shape of your cornea can change, as can the focusing power of your prescription.

See your provider if you have seasonal allergies that make wearing contact lenses difficult or uncomfortable, or if you develop an allergy to a particular contact lens solution.

Do not

• Sleep in daily wear lenses

• Trade contact lenses with another person

• Swim while wearing lenses

• Put lenses in your mouth, use tap water, distilled water or any homemade saline solution to moisten lenses

Special Concerns for Children With Contact Lens Irritation

Check with your children or check their lenses to see if they are suffering from dryness, itching or eye discomfort they have not mentioned and to see if they're wearing split or damaged lenses.

Self-Care Steps for Contact Lens Wearers

• Always wash your hands and dry them thoroughly before putting in or taking out your contact lenses.

• Carefully follow directions for cleaning your contact lenses.

• Use eye drops with a similar composition to real tears to keep your eyes moist.

• Be careful not to sit directly under or in front of heating vents. Forced air heat can cause dry eyes. If you're in a car, push the vent away from your face.

• Use humidifiers in your home to combat dry air.

• Inspect your contact lenses routinely for splits and rough edges, which can irritate your eyes.

• Don't wear disposable contacts longer than recommended.

• Don't use saliva to clean or lubricate your contacts.

• Don’t swim with contact lenses.

• Get eye exams as recommended by your eye care provider, at least once a year.