Asked by: Richard Kim, via email
Not normally, but there is a condition called nocturnal lagophthalmos where a sufferer is unable to shut their eyelids when asleep. According to one review, this occurs in up to 5 per cent of adults. This can be due to a variety of factors, including protruding eyes or abnormalities of the eyelids.
There are also cases in which the cause has not been established. Noctural lagophthalmos can lead to certain difficulties, from sore eyes to more severe problems such as the development of ulcers on the cornea. Do talk to your doctor if you are waking up with red or sore eyes or have been told by someone that you sleep with your eyes open.