British scientists plan to use stem cells to cure a common form of blindness that ails millions of people around the world, with the first patients receiving test treatment in five years.

The pioneering project, launched on Tuesday, aims to repair damaged retinas with cells derived from human embryonic stem cells. Its backers say it involves simple surgery that could one day become as routine as cataract operations.

They believe the technique is capable of restoring vision in the vast majority of patients with age-related macular degeneration (AMD), a leading cause of blindness among the elderly that afflicts around 14 million people in Europe.

The improvement is likely to be great enough to transform lives, allowing the blind to regain the ability to carry out everyday tasks such as reading or driving.

Some drugs, like Genentech Inc's Lucentis, can help the one in 10 patients with so-called "wet" AMD and US biotech firm Advanced Cell Technology is looking at stem cells in other eye conditions. But there is no treatment for the 90% with "dry" AMD.

AMD is caused by faulty retinal pigment epithelial (RPE) cells, which form a supporting carpet under the light-sensitive rods and cones in the retina. The new procedure will generate replacement RPE cells from stem cells in the lab, with surgeons then injecting a small patch of new cells, measuring 4 by 6 millimetres, back into the eye. The London Project to Cure AMD brings together scientists from University College London, Moorfields Eye Hospital in London and the University of Sheffield.