14.This train that moves into or out of the tunnel, depending on which direction your mind decides it should go.
15.This water-refraction experiment.
16.Craaaaaaaaaaaaaaaap.
Do your eyes hurt yet? Screen-induced eyestrain is a real thing that affects everyone. So stop staring and go get your eyes checked by an optometrist. It's easy, painless, and your eyes will totally thank you for it.