Social media is abuzz concerning the color of a striped dress that has divided people into two types. It all began on Tumblr with a post earlier in February, stating “Guys please help me – is this dress white and gold, or blue and black? Me and my friends can’t agree and we are freaking the f*** out.” Before long celebrities were in on it with everyone from Ellen DeGeneres to Taylor Swift considering the dress colors. So what do you see, white and gold or blue and black?

Light enters the eye on different wavelengths. The first burst of light is made of whatever wavelengths are illuminating the world reflecting off whatever you’re looking at. The image of this dress, however, hits some kind of perceptional boundary. So what you see depends on the light and the context in which you are seeing the dress. Blue on a white background is seen as blue, but on the black background some people may see it as white. People who see it white (the majority) are wrong…