Hope you doing well.
There is a lot of information on closed eye visuals on google with levels explained. Is that legitimate information?
I know there are closed eye entoptic phenomenon.
Yes the section on Wikepedia on entoptic phenomena is quite good. Most people don't see them all, some people don't see any. Some can be seen with the eyes open e.g. 'flying corpuscle" or blue field phenomena
The term closed eye hallucination is not widely used or accepted. Just looking at the two articles they seem to be the entopic phenomena that occur with eyes closed. I don't like the word hallucination.