Here is a new optical illusion from Gianni Sarcone that I found while browsing his Red Bubble portfolio. If you haven’t visited it, I would encourage you to do so as there are a lot of great designs to admire.
With respect to today’s optical illusion, there are a couple of things going on.
First, the gray lines do not necessarily appear to be parallel with one another due to the angled colored lines in the background. In reality, the squares are concentric (which you can confirm for yourself by using some sort of straight edge).
Second, the background creates the impression that the concentric squares are moving and expanding slightly (especially if you shift your gaze and move your eyes around different parts of the image).
(via Gianni Sarcone)