Cataracts prevent light from reaching area of brain that sets body clock, reports The Daily Mail.

Now a new study claims patients who have their cataracts surgically removed not only see more clearly, but have a better night’s sleep too.

The study by the Nara Medical University in Japan asked 1,037 pensioners with cataracts, 174 of whom had had surgery, to wear a wristwatch-style sleep tracker device to record duration and quality of sleep.

The study found that pensioners who had their cataracts removed slept better and remained asleep for longer compared with those who had not had surgery.