Will the pair of soft contact lenses you bought recently help arrest progressive myopia' No, say ophthalmologists.
Worried at the increasing use of soft contacts by teenagers suffering from myopia, city-based ophthalmologists allege that several opticians and refractionists are “duping” students into believing that the costly lenses can actually help them control myopia, or short-sightedness.
Myopia among teenagers normally rises till the age of 19, before slowing down. But the craze among school students to use lenses to control myopia and, at the same time, “look good”, is causing more harm than good, warn specialists. “I treat students who have been using soft contacts for years, without any inkling how the myopia has progressed in leaps and bounds. By the time they realise it, it is often too late to arrest it,” says leading eye surgeon Ratish Pal of Susrut Eye Foundation.
The axial length (the distance between the cornea and the macula, or interior part of the eye) is 23 mm. In a youth suffering from myopia, the axial length starts increasing from the standard 23 mm to 25 or 26 mm. Some doctors feel that if contact lenses are placed over the cornea (average size 8.5 mm), then increase of the axial length can be restricted and myopia arrested.
“These were age-old theories. Now, research has proved that soft lenses cannot stop myopia among teenagers, because the lens takes the shape of the cornea and also gets stretched, as the curvature increases,” says Mohinder Singh, chairman of Silklens Private Ltd, which manufactures contact lenses. “We do not encourage the use of soft lenses among myopia patients.”
What doctors say could work in arresting myopia is the use of hard contact lenses. “But hard lenses are obsolete these days and rarely used,” observes Singh. Specialists say that in every 100 teenagers examined, 40 invariably turn out to be victims of one optician or the other, who sells them the costliest pair of contact lenses, ranging from Rs 1,200 to Rs 4,000. Disposable contact lenses, “which are very popular”, cost around Rs 3,500-4,000 off the display shelves.
Another specialist, professor Jyotirmoy Dutta, head of department (ophthalmology), National Medical College and Hospital, says that “students refuse to learn and often go on changing their soft lenses for years”, until myopia increases to alarming levels. “Of late, I have started explaining to parents of these students how they are being duped by opticians,” Dutta adds.
Doctors also explain that at times, convincing teenagers about the uselessness of soft contacts can prove quite hard. “I prescribe semi-soft lenses to teenagers, which are slightly harder and can stop the curvature of the cornea,” explains ophthalmologist P.B. Sarkar of Salt Lake Eye Foundation. “But I would still suggest that teenagers with myopia wear spectacles rather than contact lenses.”