Around 135 million people worldwide wear contact lenses, small corrective plastic discs that sit on the surface of the eye, MayoClinic.com reports. While contacts have many benefits, they also have many drawbacks and can cause serious complications if not properly cleaned, changed and stored. While even small children can wear contact under some conditions, other people should not wear contacts at all.
Specific Eye Problems
People who are nearsighted, or myopic, or who have significant astigmatism, often see better with contact lenses than with eyeglasses, the American Optometric Association reports. The opposite is true for patients who are farsighted, although they may have an increased field of vision with contacts. People with presbyopia, age-related loss of near vision that affects the ability to read small print, benefit from bifocal contacts or monovision, wearing one contact to correct for distance and one to correct for close vision. However, bifocal lenses work well for only around 50 percent of patients, Richmond Eye Associates warn.
Types
Contact lenses are made either of hard plastic, called gas-permeable contacts, or soft plastic, known as soft lenses. While gas-permeable contacts are harder to adapt to at first, they also allow more oxygen to pass through to your eye and cause less corneal irritation. Gas permeable contacts also last longer and correct certain refractive errors more effectively, MayoClinic.com states.
Benefits
The cosmetic benefit of not having to wear glasses is the main benefit of contact lenses for most people. Contacts also don't fog up, fall off during strenuous activities or interfere with wearing certain athletic headgear.
Disadvantages
Contact lenses may cost slightly more per year than eyeglasses, which may not need yearly replacement. Contacts can be hard to insert and remove for some people and can irritate the eye. Non- disposable contacts require cleaning with special solutions. Multipurpose cleaning, disinfecting and storage solutions should be used with caution, since several brands have been withdrawn from the market due to increased infections, MayoClinic.com warns. Lens cases require replacement every three to six months. Allergies to the contact lenses themselves can develop, as well as allergies to the solutions used to care for lenses.
Complications
Contacts can cause significant injury to the cornea of the eye, especially if worn too long or not properly cleaned. Serious complications include corneal ulcers, an infection that causes pain, redness, light sensitivity, tearing and blurred vision, Richmond Eye Associates explain. A permanent decrease in vision can result from scarring even if antibiotics are given to treat the infection. The cornea can also swell or become misshapen due to contact lens use.
