Is it normal for toddlers to sleep with their eyes open?

The first time I saw my toddler sleeping with her eyes open, I felt very alarmed by her glassy, zombie-like stare. I couldn't help but worry that she might have some sort of brain damage or neurological problem. Fortunately, her eyelids stayed shut when I gently closed them for her.

The fifth time I noticed my toddler sleeping with her eyes open, I mentioned it to my mother and grandmother. Both of them reassured me that I had done the same thing when I was a young child-- and that many of my siblings and cousins had done so, as well. Open-eyed sleep appears to run in my family as consistently as olive skin and bad tempers.

As it turns out, toddlers who sleep with their eyes open-- a behavior known medically as nocturnal lagophthalmos-- are only very rarely demonstrating symptoms of a physical or neurological problem. According to BabyCenter.com, many babies sleep with their eyes open, but most outgrow nocturnal lagophthalmos by twelve to eighteen months of age.

BabyCenter advises parents to contact a pediatrician if their toddlers continue to sleep with their eyes open beyond twelve or eighteen months of age, because it can rarely be a sign of a deformity of the eyelids. Even more rarely, a child may be unable to completely close his eyes because of facial nerve problems. However, it's unlikely that you have anything to worry about if your toddler sleeps with his eyes open. Many children continue sleeping with their eyes open well into their school years, and some adults even do it on occasion.

No one is entirely sure of why some babies and toddlers sleep with their eyes open. BabyCenter suggests that it may relate to the amount of time that young children spend in REM sleep-- the phase of a sleep cycle in which dreaming occurs. People spend progressively less time in REM as they grow older, and most children gradually outgrow nocturnal lagophthalmos as they develop more grown-up sleep patterns.

If your zombie-kid's sleeping behavior gives you the heebie-jeebies, try gently tapping her eyebrows or pressing on her eyelids. Your toddler will most likely keep her eyes closed for the remainder of her nap. If you're still worried, never hesitate to ask a licensed health care provider for an evaluation; a quick exam can rule out the possibility of an underlying problem.