A man who lost sight in one eye in a fight 15 years ago has had his vision restored by British scientists using stem cells.

The treatment, which has been developed at Newcastle University, could help thousands of people who suffer severely impaired vision through a condition known as Limbal Stem Cell Deficiency. The condition is caused by damage to the surface of the cornea from disease, chemical burning or physical injury.

Russell Turnbull, whose right eye was burned in an ammonia attack after he intervened in the fight on a bus, is one of eight patients who have undergone the stem cell treatment. He said: “This has transformed my life . . . I'm working, I can go jet skiing and also ride horses.

“The operation has improved the sight in my right eye from 10 per cent to 90 per cent. Best of all it has removed the constant pain and light sensitivity.”

Stem cell research with embryos has long been controversial, but this technique uses a patient's own cells. The Newcastle team took a small biopsy from the cornea of Mr Turnbull's good eye and multiplied its stem cells by 400 times. When the cells were transplanted back into the damaged eye, they restored the cornea.

Sajjad Ahmad, the scientist who developed the technique, said its success showed the scope for using the patient's own stem cells to treat the eye. Details are published in the journal Stem Cells. However, the technique depends on having a healthy eye from which to extract stem cells and is not suitable for retinal problems such as macular degeneration.