By Thomas Moore, health correspondent
A new microwave treatment that heats the eye could prevent hundreds of patients a year needing a cornea transplant.
The procedure corrects rugby-ball eye - the abnormal shape caused by keratoconus, a degenerative condition that affects 30,000 people in the UK.
Around 500 a year develop such severely distorted vision that they need a cornea transplant.
In the new treatment specialists use a microwave probe to heat the cornea to around 60 Celsius.
The temperature causes the front of the eye to shrink, restoring a normal spherical shape.
This is then 'locked-in' with a burst of ultra-violet light, preventing further deterioration of the eye.
Imran Rahman, consultant ophthalmologist at the Manchester Face and Eye Clinic said many sufferers have such distorted eyeballs that they are unable to use normal contact lenses or spectacles to correct their vision.
But he told Sky News that the new keraflex procedure is highly effective: "The difference in the visual acuity can be remarkable.
"We hope patients have really good unaided vision, something they have not had for many years."
Keratoconus usually affects young people. Carl Evans, 27, suffered from double vision and was warned he was likely to end up on the transplant list.
He's had one eye treated with keraflex and now hopes to have the other one done as soon as possible.
"I wasn't expecting it to work so well," he said. "I wasn't able to see the top letter on an eye chart from a metre away.
"Now I can read four or five lines and read a newspaper without having to squint as much. So it has been a big improvement."
But The Royal College of Ophthalmologists said more trials are needed to confirm the benefits of the procedure.
President Professor Harminda Dua said: "It is promising but we want to see more research to show it is safe and effective in the long term."