So, last night, us citizens of the Internet collectively lost our minds over a picture. Cat pictures? Leaked celebrity nudes? Pictures of llamas? (Well, yes actually, that happened as well.) Some daring red carpet attire?

No, I’m talking about this picture, of course:

It turns out that some percentage of (WRONG, WRONG, ABSOLUTELY WRONG) people see that dress as blue and black. Another percentage of people, looking at the exact same picture, see that picture (CORRECTLY I MIGHT ADD) as white and gold. (Many people report having seen both, or being able to switch back and forth between the two.) (Spoiler alert, the dress actually is blue and black.)

It takes quite awhile to get over the fact that this isn’t some kind of massive Internet hoax. You should see the looks on people’s faces when I tell them that, to me, that dress is white and gold. The progression from disbelief (“Are you stupid?”), to suspicion (“Why are you playing stupid? What’s your angle?”), to pity (“Oh you are stupid, you poor simple thing!”) which flashes there before they have a chance to hide it is actually kind of frightening. (Now I know how you really feel about me!) When you see something with your own eyes, it is fact. Seeing is believing. How could anybody disagree? It is, quite literally, as plain as the nose on my face.

I might not have believe it either, except that Sara sees blue, even when we are looking at the exact same picture at the exact same time. There’s like this weird moment where we realize, we’re not seeing the same thing and calling it different words, we’re actually experiencing different things. And then my mind melts.

I’ve read quite a few “explanations” about why this happens, and, needless to say, they left me a little underwhelmed. They mostly consist of a “vision expert” saying, “Rods and cones. Rods. And. Cones.” So I’ve pieced together the best articles, and what I’ve come up with is this:

Seeing is actually quite difficult, and in the nanosecond between when your eyes experience light bouncing off something and you “see” it, your brain does some processing. Depending on what your brain expects to see, it may modify the input just a little bit, to give you a “better” image. This gives rise to the many optical illusions that you’ve probably seen elsewhere in books, science museums, or the Internet.

This particular case is a combination of the actual equipment of your eyeballs and the split second of processing in your brain. If your eyes are good enough, you detect enough blue for your brain to say, “This is a blue dress under yellow light”, and that is the image you “see”. If your eyes are just on the other side of that magical tipping point, your brain says, “this is a white dress under blue light” and helpfully color-corrects the image for you.

This dress is just perfectly, accidentally, right on that tipping point such that some people go one way and some go the other. Some can “trick” their brain into falling one way or another by changing the brightness on their monitor, or looking at something blue or white first, before looking at the dress.

As to why your brain “changes” what you are seeing, it is really trying to help you. As I said, seeing is a difficult thing. All colors are based on seeing which light reflects from something. A red shirt is absorbing all spectrums of light except red; observers see the reflected red light and say, “Hey, that’s a red shirt!”

Imagine the red shirt is up against a white wall. Now imagine that the only illumination in the room is a red light bulb. The shirt is still reflecting red light, but now the white wall is *also* reflecting red light. And so your brain has to decide: did the wall suddenly become a red wall, or is it a white wall with red light reflecting off of it?

When you look at the dress, your brain is very quickly trying to decide which scenario you are actually seeing: a blue dress under yellow light, or a white dress under blue light. Some brains pick one, some pick the other, and some change their minds based on other things (such as recently seeing something blue).

The fact that two people can actually see the same thing differently is fascinating to me. It’s like we’re not living in the same layer of reality. And that’s not even taking into account animals with acute senses of hearing or smell, or who can see into the ultraviolet, or senses we can’t even imagine, like electromagnetic detection. Who knows how those animal perceive the world differently than us? For that matter, who can say what else we are experiencing differently?

(My wife, for lack of a better term, lives in a much “smellier” world than I do. Is it because my nose has died inside after being subjected to years of my own reek, or because her brain is causing her to BELIEVE she is smelling things that she can’t possibly be smelling because they don’t exist and that is ridiculous? WE CAN NEVER KNOW.)

We used to have a bag that I insisted was purple, and Sara insisted was blue. It kind of became a running gag; however, we both ultimately assumed that we were seeing the same thing, but calling that thing a different name. In the aftermath of “the dress”, however, I am forced to conclude it is possible that we were actually experiencing legitimately different colors. Experiencing a different reality.

And, also?

It’s still white and gold.