Open-eyed sleepwalking

Officially named lagophthalmogic somnambulism, open-eyed sleepwalking is a condition in which a person is awake, but appears so exhausted and worn out that they may very well just be sleepwalking with their eyes open.

John: What’s wrong with Richard?
Sam: He’s open-eyed sleepwalking. He had to stay up all last night working on some ASL assignments.
John: Poor guy…