Brit scientists have discovered the gene that could prove to be the glaucoma trigger. Glaucoma is a common eye disease that causes blindness.
Researchers predict it may soon be possible to screen people's DNA to find out if they are at high risk of suffering from glaucoma.
They would be able to get help as soon as they notice any changes to their sight, ensuring they receive treatment quickly.
This can damage the optic nerve, which connects the eye to the brain. If diagnosed and treated early, sight can be saved.
But many patients fail to recognise the symptoms and go blind.
In the latest study, a team from Southampton analysed the genes of more than 34,000 people in Iceland and compared their genome to those of 1,200 patients with open-angle glaucoma.
They found that a gene was linked to an increased risk of suffering the condition.
"Our work in helping identify a novel gene and biological pathway for glaucoma is an important step forward in making progress in this disease," the Daily Express quoted Professor Andrew Lotery, who was part of the team from Southampton General Hospital and the University of Southampton which made the discovery, as saying.
Worldwide, glaucoma is now the leading cause of blindness and affects the lives of more than 70million patients.
It is thought that the risk of suffering glaucoma comes mainly from genes and age, although patients with diabetes and shortsightedness are also at increased risk.
The study has been published in the journal Nature Genetics.