BBC News Online: Health

Eyesight problems 'genetic'

The breakthrough could lead to new treatments to prevent problems before they occur.

The research was carried out by the Twin Research Unit at St Thomas's Hospital, London.

Lead researcher Dr Chris Hammond said: "The genes we inherit from our parents are an important factor in deciding whether we will need glasses.

"We hope that this research will lead the way to identifying some of the genes involved, so that we can understand why short sight happens, with a view to being able to prevent it in those who are susceptible in future."

Increase in cases

An increase in short-sightedness, or myopia, is costing many billions of pounds worldwide.

The World Health Organisation estimates that up to 20% of children in developed countries need glasses and in Singapore and Japan two-thirds of all teenagers have significant myopia.

Dr Tim Spector, director of the Twin Research Unit, said: "The reasons for short-sightedness becoming more common have been speculative.

"They may include children being exposed to more intensive reading, schoolwork and computer games, but this study proves that genetic susceptibility is a major factor in a large number of cases."

The research is published in the journal Investigative Ophthalmology and Vision Science.