Not that I’ve ever done acid, but I imagine if one were to do acid this would keep the eye occupied for a good long while.
Kaleidoscope. As a kid, do you remember those paper tubes with the crystals in the bottom, you hold them up to the light and turn the base to get a lovely array of ever changing colors and patterns? My aunt sent this to my mom who in turn sent it to me =) Family sharing! And now I’m sharing it with you. It’s a computer generated kaleidoscope. It’s really just pretty and cute. If you run your cursor across the image (which is already in motion) it changes as well. Enjoy!