Contact lens, also known as soft lenses, are small, thin lenses placed just above the cornea on the eye’s surface. Contact lenses are often ophthalmic prosthetic devices used by more than 150 million people world-wide, and they are worn to correct visual defects or for therapeutic or cosmetic reasons. The most popular form of contact lens is the extended wear contact lens (also called a continuous-wear contact lens), which is prescribed for those whose eyes need considerable stretching to accommodate corrective lenses. Other forms of contact lens are toric contact lens and half-moon contact lens.
Contact lenses were invented in the early 1900s by Dr. William Rice, who improved upon the techniques used by his colleague Dr. J.E. Berry to design and manufacture contact lenses. Initially, Rice’s lenses were rejected by several practitioners and were considered to be unattractive and even a health risk. However, wearers of these first lenses found the comfort and ease of wearing them. In subsequent years, lenses became available for all kinds of wearers, including sportsmen. Ever since, they have become more common and are widely used.
It is recommended that new lenses are prescribed by an optometrist or ophthalmologist, as prescribed lenses may result in discomfort or worse, vision damage. This is especially true if prescribed lenses do not fit well or are not cleaned properly. It is also recommended that prescribed lenses be worn for a certain period before being discarded.
Eye infections such as “Keratitis” are common among users of contact lenses. Keratitis is an inflammation of the keratotic glands, which are the tiny hair-like structures that line the eye. Keratitis can affect any part of the eye, but is most common in the conjunctiva (the outermost layer of the eye). The primary cause of keratitis is excessive dryness of the conjunctiva, which results from the constant exposure to saliva-water mixture produced by the body. Although most cases of keratitis are alleviated when the user begins an effective lens cleaning regimen, in some cases, complete eradication of the condition is required.
As with all other forms of contact lenses, improper or incorrect use of contact lenses can cause adverse effects. Eye irritations and infections are common with contact lens wear, although cases are usually fewer and far between. New technologies and improved manufacturing processes have resulted in fewer cases of irritation and infection.
One of the most important benefits of wearing contact lenses is that it offers a natural alternative to traditional eyeglasses. Contact lenses provide a wide array of visual improvements and allow users to avoid a dependence on glasses or contact lenses. However, care should be taken not to wear contacts in or near the eye. Wearing lenses in or near the eye may result in irritation or infections, especially when hands are excessively cleaned or ill.