Children's lazy eyes corrected with eye-patch over shorter period of time

British researchers say correcting a child's "lazy eye" with an eye patch all day to correct their vision, may be unnecessary.

The eye disorder amblyopia, also known as "lazy eye", is quite common and affects one in every 500 children.

It means one eye does not see properly despite wearing glasses and left untreated the condition can lead to a loss of vision.

As a rule the problem is treated by the child wearing a patch over the good eye for a period of time each day, forcing the other eye to become stronger.

Doctors in the past have sometimes recommended children wear a patch for a period of years but now experts say wearing an eye patch for just three hours a day for 12 weeks is sufficient to resolve the problem.

In a study conducted by researchers at the City University in London, eighty children with the condition were told to wear their patch for either six or 12 hours each day; the researchers also monitored how often the children actually did wear the patch.

They found that wearing the patch for three to six hours a day was as effective as wearing it for six to 12 hours a day and they also discovered that children under four required much less time wearing a patch than older youngsters.

According to health researcher Catherine Stewart and colleagues the analysis suggests achieving an initial dose rate of three to four hours a day should be a clinical priority.

The researchers say the response depended on the child's age and for children under four years this could be reduced.

They say patching beyond twelve weeks did not confer additional benefit.

The researchers also say eye patching can cause considerable distress for both the child and family and doctors should try to minimise the amounts necessary for the best expected outcome.

The study was published online by the British Medical Journal.