Tube Optical Illusion

Is the black spot growing?

See Another Random Optical Illusion

Scroll down for the explanation.

Most people say that it does grow as you look at it.

Explanation

Here we're providing a simple perspective optical illusion showing how the rings, as they get closer and closer together, give us the sense of a 3D tube going deeper and deeper. We do not currently have a good explaination why the black grows.