Children could be cured of short-sightedness by wearing soft contact lenses at night which re-shape their eyes to prevent them ever needing glasses, a study has shown.
Trials involving more than 300 children in Britain and across the world showed that the lenses can stop the eye becoming misshapen which leads to myopia.
In April, a study published by Ulster University found that the rate of short-sightedness in Britain has doubled over the past 50 years, because children no longer spend enough time outdoors.
Twenty-three per cent of British 12 and 13-year-olds now suffer from myopia which causes distant objects to appear blurred, while close objects can be seen clearly - compared to 10 per cent in the 1960s.
However a new study has found that contact lenses can stop the progression of myopia, a practice known as Orthokeratology.
The lenses, which are removed each morning, control the shape of the eye so that it grows in the correct manner so that glasses are never needed.
None of the children within the study suffered further change in their vision during the three year trial period although all of the control groups rapidly deteriorated.
"Parents who are worried about myopic progression in their children now have a viable option,” said Professor Pauline Chom, of The Hong Kong Polytechnic University, which carried out one of the trials.
“Orthokeratology has been shown to effectively slow the progression of myopia in children."
The onset of short-sightedness generally occurs in childhood and about one in three adults has the condition, which means distant objects are out of focus.
In addition to requiring corrective lenses to see clearly, people with myopia are at higher risk for retinal detachment and glaucoma.
In people with normal vision, the eyeball grows along with the rest of the body and is programmed to stop growing at a point that sustains clear vision.
In people with myopia, the typically spherical eyeball becomes elongated, resembling the shape of a grape or an olive.
Children who will grow up with normal vision are actually slightly far-sighted when they are aged six, so the potential for future myopia can be detected at a young age via a refractive error measure that reveals little to no far-sightedness.
The iGo OVC contact lenses are now available at opticians in the UK from the age of seven.
“We have whole families using lenses with some children starting to wear the overnight lenses from as young as 6 years old and who are now aged 13 without experiencing any increase in their prescription," said Jennifer Golden, Co-Founder and Director at iGO Optical who market the lenses in the UK.
“The children who wore overnight lenses suffered minimal deterioration in their eyesight over three years.”
Gordon Ilett, a representative from the Association of Optometrists, and a specialist in children’s eyesight, called for more testing of the lenses.
“It is emerging technology and there is lots of anecdotal evidence about how brilliant it is, but really we need large population studies to prove efficacy,” he said.
“Is there risk involved? Yes there is with overnight contact lenses, probably around 15-20 in 10,000 risk of corneal ulceration, an infection in the front of the eye. Daily contact lens wear is about 2 in 10,000.
“If you intervene when a child is just starting to become short sighted, then clinically you can justify it as you are correcting a defect of sight. But is it ethical to intervene and fit them in a child whose family are all short sighted?”
Experts have recently called on schools to begin teaching children outdoors to save their vision.
Experts at the Beijing Institute of Ophthalmology, Beijing Tongren Hospital, who have been trialling the glass box school classrooms and allowing youngsters to have lessons outside have already found that it has reduced myopia by 23 per cent.
Previous studies have shown that hunter gatherer societies which live mainly outdoors, such as tribes in Gabon, were found to have the smallest levels of myopia, just one in 200 members suffering from the condition.
The research was presented at the British Contract Lens Association annual conference.