Eyesight can deteriorate with age

Scientists in Australia have developed a gel which they say reverses the deterioration in sight associated with getting old.

It could also offer an alternative to surgery for people with cataracts, which can lead to blindness.

The gel is used to replace the contents of the eye's lens, which over the years can harden and reduce vision.

Scientists in the United States first demonstrated in the late 1980s that replacing the contents of an ageing monkey's lens with silicone oil could restore its ability to focus.

But since silicone oil leaks it was never going to have any practical use in humans.

Animal tests

Now scientists at the Australian Government's multi-national Vision Co-operative Research Centre (Vision CRC) have developed an alternative to silicone oil.

It has already been tested successfully on rabbits, according to New Scientist magazine. There are now plans to test it on monkeys before possible human trials.

We should begin human trials by the end of next year Arthur Ho, Vision CRC

"In the best-case scenario, we should begin human trials by the end of next year," said Arthur Ho of Vision CRC.

Implanting the gel would be very similar to current cataract surgery, except that the lens is not replaced.

Instead, after making a small incision in the cornea, a doctor would cut a tiny hole in the lens capsule and suck out the contents.

The gel, which has the consistency of thick oil, is pumped in and a burst of UV or visible light transforms it into jelly.

"This could be a quick 15-minute procedure," said Mr Ho.

Hugh Taylor, director of the Centre for Eye Research Australia in Melbourne, said: "This technique has enormous potential.

"It will totally change ophthalmic surgery, if we can get it right."