Nobody can answer that without a detailed exam... Can be lagophthalmos, can be dry eye, can be blepharitis, can be very mild ABMD, etc. All depends on clinical findings.
Originally Posted by apham
Yes, people with dry eye syndrome (of whatever type) often have drier eyes at night. It's normal for tear production to be reduced while you sleep - remember you're not blinking all the time so you're not pumping out as many tears. For healthy eyes that's OK but for people with a compromised tear film of any kind, it can be a real problem, with or without a lid closure issue. And people with a totally healthy tear film can sleep with a very slight lid opening without it causing them serious problems.
If you can, try to book a dr. appointment that will be the very first in the morning. If you get an early appointment, they can sometimes see signs of exposure under the slit lamp, literally a line across part of your eye from your lids not closing, if that's part of your issue.
The Dry Eye Zone