Starting on February 26, 2015, millions of people viewed an accidental optical illusion that went viral on the Internet. The popularity of The Dress illusion was due in part to the fact that the public was split between people who can see the illusion and people who can’t. It all depends on whether you see the dress as white and gold or blue and black.
The actual color of the pixels in the lighter part of the dress are blue, and that is all that some people can see, so for these viewers there is no illusion. Others see the lighter part of the dress as white, and for them what seems to be happening is an illusion similar to the banana illusion. That is, their brains perceive the dress to be in a blueish shadow, and “correct” the blue color to white. Some people report being able to switch from seeing white and gold to seeing blue and black.
This is one of the more difficult optical illusions to present, because I happen to be one of the people who cannot see the dress as white and gold. In the case of the banana illusion, the proof that I created looks appropriately trippy to me. I know it’s the same color from one side to the other, but it seems to change from yellow to blue. In the case of the dress, I have created something similar below, but it’s hard for me to know what it looks like for people who can see the illusion. In the proof below, both circles contain the exact same pixels, and to me they look the same. So, people who see the dress as white and gold, do you see the circle on the right as blue?
What would be really interesting is if someone could come up with a way for people who do not see the illusion to see it. Even in the images I have seen online where people have purposely lightened the image to make it appear whiter, it still appears to me to be a very light blue.