Fashion fad could cause blindness
They are a fashion statement worn by thousands of clubbers every weekend.
But health experts today warned that coloured contact lenses could cause damage to eyes and in some cases lead to permanent blindness.
Costing around £30 a pair, the lenses are often worn for several hours at a time. But researchers found that, after only two hours, irreversible damage occurred in some wearers.
The lenses are freely available via the internet, market stalls and high street shops throughout the country. Because they are not properly fitted by an optician they can rub the cornea, causing infection and scarring and even loss of the eye, experts claim.
Tens of thousands of teenagers in Britain are believed to use such lenses every weekend, although exact numbers are impossible to gauge due to the lack of controls on sales.
They come in many colours and patterns, including Union flags, glow-in-the-dark and even snake-eye styles.
At the moment the lenses, which do not alter the wearer's vision, may be legally sold by anyone. However, in a forthcoming issue of the American journal, Eye And Contact Lens, the lenses are described as a "reckless endangerment".
Dallas-based ophthalmologist Dr H Dwight Cavanagh, author of the report, said: "A lot of permanent damage can be done after only a few hours of wear. Buying contacts in this onesizefits-all manner without a prescription is dangerous and can be detrimental to eyesight."
He said: "Letting an under-age member of the family use these lenses without supervision is like giving them the car keys without a licence and without an adult in the front seat."
In addition to the infection and damage that can lead to inflammation and blindness, the scarring such ill-fitting lenses can cause may be irreversible, said Dr Cavanagh.
Now the Federation of Ophthalmic and Dispensing Opticians has called for new legislation to be introduced forcing people to visit an optician to buy them.
Bob Hughes, the federation's chief executive, said: "The eye is a very sensitive thing. To put just anything into your eye is not advisable. Education is the key. If lenses are fitted and looked after properly, there is absolutely no problem with them. But if you buy them from a market stall or over the internet, proper care is unlikely.
"We have heard of many people swapping lenses with friends and even licking their lenses to clean them. That really is putting the eyes at risk, as it's incredibly easy to pick up infections. That is why most modern contact lenses are disposable."
Contact lenses, prescribed or not, are pieces of plastic that prevent normal amounts of oxygen from reaching the eye. Use of lower oxygen-transmitting lenses can cause the cornea's outer layer of cells to react in such a way that harmful, infection-causing bacteria is bound to the eye.
