London: Scientists have developed a tiny implant, no bigger than a pinhead, which sits inside the cornea to reverse vision problems in ageing eyes. As some people age, their ability to switch focus between near and distant objects diminishes, a condition known as presbyopia.

It can skew the perception of depth and makes reading in poor light impossible. Now, scientists have developed a tiny implant that sits inside the cornea and slightly increases its curvature, to allow the eye to focus again. Known as a Raindrop corneal inlay, the technique was developed by scientists at ReVision Optics in California but the first operations have now been carried out at a clinic in Leamington Spa, Warwickshire, 'The Telegraph' reported.

The inlay is called Raindrop because it is the shape of a droplet and is made of a substance called hydrogel which is also used in contact lenses. Hydrogel is 80 per cent water which makes it more compatible with the eye than other corneal implants. Until now, the only long-term treatment for presbyopia has been laser surgery, but sufferers are still likely to need reading glasses when the light is poor.

The results are often not permanent because lasers remove part of the cornea to reshape it, and so the problem can return as the lens flattens out again. The new operation, which costs 2,495 pounds, is quicker, taking just 10 minutes, whereas laser surgery can take an hour.