How can you sleep with eyes open?

I know my uncle sleeps standing but his eyes are closed when he sleeps. Can you call it sleep when eyes are wide open?

Sleep-one of the mysteries for us has in fact several mysterious and amazing facts. Do you know my husbands sleeps only three hours daily and still remain active throughout the day?

Do you know that people can take cat naps with their eyes open without even being aware of it?
Here is another amazing fact:
Some scientists believe we dream to fix experiences in long-term memory, that is, we dream about things worth remembering. Others reckon we dream about things worth forgetting - to eliminate overlapping memories that would otherwise clog up our brains.

Read more marvelous facts about sleep in the National Sleep Research Project.