Contacts see many changes

Terry Herbig / staff / digital Improvements are being made almost continuously to make contact lenses more comfortable and longer lasting.

The quest for better vision has led millions of Americans to the contact lens, a tiny plastic sphere worn over the cornea of the eye.

Although contact lenses have been around since the 19th century, they did not become popular until the last half of this century. No wonder -- early contact lenses were very large, made of glass and fit over the entire eye.

They were worn by people who could not get good vision any other way -- even from eyeglasses, according to Drs. Walter Zinn and Herbert Solomon, authors on eyecare, eyeglasses and contact lenses.

Transparent plastic lenses became available in the 1940s, but were still very large. The introduction of the thin, small lens covering the cornea was the breakthrough making it possible for more people to fitted.

A Chicago man, Dr. Newton Wesley, and Dr. George Jessen popularized the use of the contact by giving seminars on how to fit the lenses. They also appeared on national television programs such as ``The Steve Allen Show.''

Today, an estimated one in 10 people, or 29 million people, wear contact lenses in the United States, according to Dr. Janice Jurkus, a faculty member of the Illinois College of Optometry.

People generally choose to wear contact lenses for one of two reasons: cosmetic purposes, or to see better than they would with traditional eyeglasses.

People who are highly nearsighted or highly farsighted tend to function better with a contact lens, worn just a tear-drop away from their eye, rather than through eyeglasses. The lens of an eyeglass tends to be a distance of 13 to 15 millimeters from the eye. The contact lens reduces the amount of distortion from pen rays of light.

The quest for better vision has led lens makers to introduce several new kinds of contact lenses every year, Dr. Glenn Darlington, a contact lens specialist with Eye Surgeons Associates P.C. in Silvis, said. Some materials allow for more oxygen to pass through to the eye, while others are less likely to collect deposits.

Bausch and Lomb introduced the first soft lens, made from a material called Polymacon, in 1970, Dr. Darlington said. This early soft lens was made from an extremely durable material, but was prone to collect deposits. The softer materials have led to an industry debate over the length of the wearing time for a contact lens.

After the incidence of cornea ulcers increased significantly from people wearing soft contact lenses for up to 30 days, the Federal Drug Administration determined that was not a healthy practice and reduced its approved time to seven continuous days of wearing.

Perhaps the biggest factor leading to the growth of contact lens use in the last eight to 10 years was the introduction of the disposable lens, Dr. Darlington said.

Age is not as much of a factor for wearing contacts as is responsibility, Dr. Darlington said. He has fit 12- or 13- year-olds with the desire to change their appearance, providing they are motivated to take care of their eyes and the lenses.

Dr. Darlington also has put contacts on infants for medical reasons, usually those who have had cataract surgery. Older adults who have cataracts generally receive an implant during their surgery, and then may only need reading glasses for close-up work.

Among the new advances on the horizon are a ``much safer, extended wear'' contact lens, Dr. Jurkus said. It is hoped the new lenses may be worn continuously for a month, as manufacturers perfect a lens that allows for more oxygen penetration and the repulsion of bacteria and other materials that tend to deposit on lenses, she said.

Other breakthroughs known to Dr. Jurkus are a new-design bifocal contact lens, and a new gas permeable lens that enhances comfort and improves sharpness of vision.