Katherine Jenkins has revealed she suffers from a medical condition which means she sleeps with her eyes open.
The opera singer is among 10% of the population living with Nocturnal Lagophthalmos, and has been unable to fully close her eyes when she sleeps since she was a child.
Katherine revealed she is a sufferer whilst telling an anecdote about chat up lines during a recent interview.
She explained: "The best chat up line to ever come my way is: 'Was you father a thief because he must have stolen the stars from the skies and put them in your eyes?' Speaking of which I always sleep with my eyes open.
"My eyes don’t close properly - they are always at least half open - and when I go to sleep I look like I’m still awake. And I don’t really have dreams either. My Mum would always say: 'Katherine, are you awake or are you asleep?’"
It is not known what exactly causes Nocturnal Lagophthalmos, but infections, genetics, traumas and strokes can all lead to the condition.
Sufferers are more likely to experience blurred vision and more frequent eye infections as a result of less lubrication on the eye to wash away dust and bacteria.