Australian researchers said Tuesday they had discovered a gene associated with long-sightedness, a development they said could lead to drug treatments that will replace glasses.

Scientists at Melbourne's Centre for Eye Research Australia said the hepatocyte growth factor (HGF) gene provided important insights into the biological mechanisms involved in sight.

"Currently, the only treatments available for long-sightedness are glasses, contact lenses and laser techniques," lead researcher Professor Paul Baird said.

"We hope this important gene discovery will help us develop new drug treatments and I expect it will have a profound impact on improving global eye heath."

Scientists at the centre, which is affiliated to the University of Melbourne, studied the DNA of 551 Australian adults to identify the genetic variations associated with long-sightedness.

It is not known what causes the condition, which leaves people seeing objects clearly at a distance but struggling with tasks such as reading, but Baird said a combination of genetic and environmental factors was likely responsible.

Baird said HGF was the first gene to be linked to long-sightedness and could give an indication of what might go wrong in the development of the eye to cause the condition, which is on the rise around the world.