Contact lenses, like spectacles, can help to correct a person’s refractive errors, such as myopia(shortsightedness), hyperopia (farsightedness), astigmatism and presbyopia (old-age vision).
There are various types of contact lenses available in the market. Most patients prefer the use of soft contact lenses. These contact lenses may be permanent lenses or disposable lenses. Disposable lenses come in either daily, fortnightly or monthly wear alternatives. Hard contact lenses or rigid gas permeable lenses allow better oxygen transmission and may be associated with less allergic response compared to the soft contact lenses, but are more uncomfortable to wear.
Problems and complications associated with contact lens wear
Contact lenses are generally safe if the person does not overuse the contact lenses and maintains strict hygiene measures. However, contact lenses may be associated with complications, some of which are potentially blinding, particularly if there is a compromise in lens care and hygiene. Some of the common and serious problems associated with contact lenses are:
Prolonged contact lens wear can result in dryness of the eye. Patients with dry eyes should be cautious when using contact lenses, as the risk of complications like infection are higher.
Allergy and giant papillary conjunctivitis
Contact lenses are foreign bodies in the eye and patients with prolonged wear often develop some allergic reaction to it. A common form of allergy is known as giant papillary conjunctivitis (GPC). The person may experience discomfort, itching, mucous discharge or redness with wearing of the contact lens. This tends to get progressively worse with continued use.
Contact lens overwear syndrome
Contact lenses reduce the oxygen supply to the cornea. People who use contact lenses for long periods or who sleep with the lenses may damage the cornea, resulting in a breakdown of the surface layer and swelling of the cornea. This results in a pain, redness, tearing and blurring of vision. In some instances, much of the surface may be left with a large epithelial defect which exposes the eye to a significant risk of potentially serious eye infection.
Contact lens infections
Contact lens infection can arise from inadequate lens hygiene or overuse of contact lenses. Micro-organisms from the contact lens may penetrate the corneal and result in a corneal ulcer. Corneal ulcers are serious because they are potentially blinding. The symptoms are pain, redness, tearing and blurred vision. Medical consultation should be sought immediately so that treatment can be instituted promptly to prevent loss of vision.
Prolonged contact lens wear can result in drooping of the eye lids.
To conclude, any contact lens wearer who experiences blurring of vision, redness or discomfort should remove the contact lens immediately. If the symptoms are significant or persist he or she should see an eye specialist promptly.