Most people will sleep with the eyes close naturally. However, some people will open their eyes when they sleep. It is the natural way and the habit. However, the open eyes will get the invisible bacterium easily which will be bad for the eyes. The next day the eyes may get infection and dryness. Some people sleep with open eyes because of the big eyeballs and loose eyelids. They could practice closing their eyes when they sleep on purpose. Then when they get used to doing such exercise, they will close the eyes eventually. They could try this and change the habit of opening eyes when they sleep.
LOL, as usual, seldom guys sleep with eyes open. If you just sleep with your eyes open once or just for a while, then you can just do it and it will not do harm for you and your eyes. However, if you do that many times, then you will get some harm for you, because as we all know that when we are sleeping, our eyes also need rest. When your eyes are open when you are sleeping, your eyes will not get dry out, which is bad fr you and your eyes. I think is is why we blink to keep our eyes filled with moisture. What's worse, you are more likely to get some eye disease if you sleep with eye open. For example, your eyes will also become glassy and irritated. Meanwhile, sleeping with your eyes open will cause the lack of muscles around your eye area. If you sleep with your eyes open, you should ask help for your eye doctor, also the surgery can also improve the problem.
Oh, no, you can't be serious. Anyway, in few cases could a man sleep with his eyes open, and generally speaking, we would not be able to sleep in bed with our eyes open. Anyway, if you try hard to keep them open, there would be some problems since your eyes tend to be drier. Or if the eye muscles of the man is impaired or got some trouble, he might sleep with his eyes open, but that is a sign of health problem, which needs to be examined.