It's not necessarily fun (nor on purpose), but yes, some people sleep with one or both eyes partially open. Learn how nocturnal lagophthalmos works in this episode of BrainStuff, based on this article: https://health.howstuffworks.com/mental-health/sleep/disorders/can-fall-asleep-with-eyes-open.htm

Why Is Siberia's Batagaika Crater Known as the Doorway to Hell?
11:10

BrainStuff Classics: How Would Authorities Handle a Murder in Space?
08:17

How Does Taste Work?
13:59