By Gareth Mitchell
Presenter, Digital Planet, BBC World Service
Playing virtual reality computer games may help treat the condition known as amblyopia, or lazy eye, say researchers.
One eye works harder than the other
In patients with amblyopia, one eye works better than the other. Because the amblyopic eye is inferior for some reason, the brain decides to use the good eye.
Over time, the neural connection to the bad eye becomes gradually weaker in favour of the good eye.
The traditional way of fixing the problem is for patients to force the bad eye to work harder by wearing a patch over the good eye.
The treatment usually involves patching for around 400 hours and can cause the eyes not to work together, resulting in double vision.
Researchers at Nottingham University say that an experimental treatment using virtual reality (VR) may offer the best of both worlds, encouraging the lazy eye to be more active and getting both eyes to work together.
"Traditionally VR has been used to present realistic environments in 3D so you imagine you're there because of the depth of the world around you," said Richard Eastgate of the university's Virtual Reality Applications Research Team.
"But we're using VR to make something unrealistic. You could call it virtual unreality," he told Digital Planet.
"We're actually presenting two different versions of the world to each eye."
In one experiment, the team has been trying out a racing game where the computer sends images of the player's own car to the amblyopic eye, but the other cars go to the good eye.
Obstacles on the track are sent alternately to each eye, so both eyes team up to get the patient through the game.
A racing game was used for the research
The researchers are encouraged by the results.
"We thought we'd develop a system that needed about 400 hours of treatment like patching. In the end we achieved the same effect in an hour," said Dr Eastgate.
It is not entirely clear how the treatment works on a neurological level.
Research in the past has tried static images. But the team believes that modern virtual reality has allowed different but related dynamic information to be sent to each eye for the first time.
"The technique hasn't been proven with rigorous trials but the early results show a very rapid effective treatment through this system," said Dr Eastgate.
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