London: Lazy eye - a condition in which one eye has weaker vision than the other - could be quickly cured by a spell in total darkness, a new study has found.
Common in young children, a visual impairment known as amblyopia, causes blurry vision in the `lazy eye`.
It happens when the part of the brain responsible for deciphering signals from one eye does not work hard enough.
It is often treated with an eye patch over the `good` eye to force the other - or rather the relevant part of the brain - to work harder. Alternatively, eye drops are put in the good eye, again to force the child to `use` the other.
Now Canadian researchers have discovered that a spell of total darkness can quickly cure the condition, The Telegraph reported.
They put kittens with induced lazy eye into total darkness for 10 days, and found they recovered.
Further examination suggested that the restoration of vision depends on the loss of neurofilaments that hold the visual system in place.
With those stabilising elements gone, the visual system becomes free to correct itself.
Darkness therapy holds promise for the treatment of children with amblyopia, the researchers said, but don`t try this at home.
They think that the darkness must be absolute to work, with no stray light at any time. It is also important to address the original cause of the amblyopia first, and to ensure that a period of darkness will not harm an individual`s good eye.
The researchers are still working out just how much darkness is required, and for how long. Regardless, they said it is unlikely that a drug could ever adequately mimic the effects of darkness that they`ve seen.
"The advantage of a simple nonpharmacological sensory manipulation, such as a period of darkness, is that it may initiate changes in a constellation of molecules in a beneficial temporal order and in appropriate brain regions," they said.
The study was published in the journal Current Biology.