I'm biased here, but this is one of the strongest visual illusions I have ever seen.
— Chris Said (@Chris_Said) January 3, 2020
None of the colored lines are moving. pic.twitter.com/QcW3u6WFB4
Chris Said brings us this stunning example of the Müller-Lyer illusion (previously at Neatorama). The colored lines are the same length throughout; only the angle of the arrows change. If you don't believe it, put a straight edge up against your screen. You can see more examples of this type of illusion at Laughing Squid. -via Nag on the Lake