I've had closed-eye hallucinations my entire life. When I was a little kid, I used to be able to see geometric patterns or just sparkles. If I pressed my palm gently over my eyes, I'd be able to change those patterns or make them pulsate. I would spend a lot of time trying to figure out what exactly I was seeing, and then end up falling asleep.

Nowadays I still have them, but they're less vivid and mostly appear as colorful specks or just as lights. It's kind of hard to put into words.