Hey guys on facebook I found this weird picture and its really weird.I suggest you try this out if it works tell me what you see.ADDED new trick try and figure this one out August 24/08/15Hope to see you try this

It's what is known as a "negative afterimage." It works by overworking certain photoreceptors in the eyes, allowing the opposing ones to take over when you shift to the white side.#pretendingIknewthatalreadyanddidntjustgoogleit

I wasn't able to see this illusion myself, but I know it works. Brain Games on the National Geographic Channel demonstrated images like these.

Edited: Original post, it's a maths trick if you guys need help then you can also give me an Private message

Interesting little trick. I've seen that before, but it's always cool. As for the math trick, I figured it out fairly easily, assuming that I got it correct. I'm not sure if I'm supposed to post it here or not to prove my legitimacy, so I'll just do three spoilers and a gray text for maximum security. First, subtract the second number from the first number. For example, 6-4 = 2. Then add the two numbers together: 6+4 = 10. Place your second answer after your first to get the number on the righthand side: 210.