You did suggest Olivia that the eyeball might explode when a person died. This is very unlikely. Look at the eye image below and try to identify the muscles in the eye. they will be attached to the two things that are constantly changing in the eye.
There are muscles attached to the lens and the iris.
When you die, your muscles relax. This causes the iris muscle contracts when this happens the eye is said to dilate ….like the image below
This is probably what your eye would look like when you are asleep. Thanks for the question.