Including what it does—and doesn't—say about your vision.
Blue and black? Or white and gold? Yesterday the social media world erupted in an intense debate over a photograph of a dress, originally posted on Tumblr, that appears to be two different color combinations depending on who looks at it. As of this morning, about 70% of people who'd taken a Buzzfeed poll see white and gold, while about 30% see blue and black.
According to a Business Insider interview with the woman who posted the photo and later saw the dress in person at a wedding, the sheath is actually blue and black. (But even the wedding guests couldn't agree, the New York Times reported.) Both Mashable and Wired have credited the photo's overexposure and poor white balance for making the dress look much lighter than it is in real life—but that still doesn't explain why some people see the dress's true colors, while others essentially see what the camera (incorrectly) documented.
So we polled a few experts on color and vision for their take on #thedress debacle.
Yes, some people see colors differently
When two people can't agree on what they're seeing, it can certainly be because of physical differences in their eyes, says Beau Lotto, PhD, a London-based neuroscientist and color researcher. About 1 in 12 males and 1 in 200 females has a color deficiency (often called color blindness) that makes them confuse red and green, for example. An even smaller percentage of people have trouble distinguishing between blue and yellow. And research suggests that men and women see colors slightly differently, as do people of different ages or in different parts of the world.
And visual perception can vary greatly, even among people who don't have color deficiencies or other obvious differences, says Mark Jacquot, OD, clinical director for LensCrafters. "Cone cells in the eye are typically responsible for the way we see color," Jacquot says. (Rod cells are more involved with movement and peripheral vision.) "Those cone cells are organized differently in different people, and can cause people to see different colors or different versions of colors, even in the same lighting."
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How our brains can muddy the waters
But another large part of how we perceive color is the way our brain sees an object in relation to its surroundings, Lotto says. (Watch his TED Talk on this topic.) And because our brains all work differently and we're all trained to notice different things, it makes sense that two people might see two very different things when looking at the same object.
"Your brain is always using context and seeing the relationship between many different colors, not just one thing in isolation," Lotto told Health. "People who see the dress as white and yellow will notice that the light is shifted toward blue, but in the context of the entire photograph, their brain tells them that this is really a white surface and a yellowish surface."
People who see it as blue and black, on the other hand, may be subconsciously noticing different details in the background or in the dress itself, so their brain shifts in the other direction. "They could be using more local context to get a sense of what's happening—noticing how that gold bit causes the white to look bluish." (For the record, Lotto sees gold and white, tinted with blue.)
Lotto also says that our past experiences—immediate and distant—can influence how we see things like color and saturation. "Some people could look at this dress having just looked at something very bright or very dark, and that will alter the perception of what they're seeing now." (Think about how your vision changes after being in a dark movie room for several minutes, he says.) This may also explain why some people have reported seeing different "versions" of the dress when they looked at it a second or third time.
Even when I told Lotto that my husband and I had done the same activities in the same settings together (going for a walk, watching television) before looking at the dress, and that we still saw very different things, he wasn't surprised. "You have different ways of thinking about things," he said. "He could be in a moment where he's very concentrated locally on that TV program and you're thinking more globally about big thoughts. That will alter the contextual relationships that your brain uses when you look at a photograph."
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Why reality isn't always what it seems
As much as it has become an Internet sensation, Lotto says this "illusion" isn't anything out of the ordinary; in fact, he says, people see colors differently all the time. "This is no different than any of our perceptions, it's just that sometimes we become much more aware of them than we normally would be."
Sara Luckey, a photo retoucher at People, notes that reality isn't always what it seems—especially with photographs. "To me, looking at this dress is like seeing a white horse photographed next to a red tent. The horse appears pink, but common sense tells us that horses aren't pink, it's just the lighting." (She told me she originally saw a "white/gold dress photographed in cool shadow lighting, making it appear bluish." She said she looked at the image again later and saw it as very black and blue.)
Luckey notes another, less drastic example: Reese Witherspoon's Oscars dress, it turns out, was actually an ice blue color, not white. "In most the photographs on the Internet, it looks—or was corrected to be—white. That's why it's so important for magazines to get confirmation from a stylist about the actual colors before we correct them ourselves."
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What it does (and doesn't) say about your vision
Other experts have weighed in on #Dressgate, as well. Neuroscientists interviewed by Buzzfeed and Wired agree with Lotto that our past experiences and individual perceptions of light and color are likely the main factor. But color and vision researcher Jay Neitz told Vice that while perception differences from person to person are normal, this example is a "huge difference" that "really takes the cake." (He also joked that instead of curing blindness, he's going to devote the rest of his life to figuring out this mystery.)
One theory that's been posted on several forums and social media sites suggests that people who see blue and black have "more high functioning" retina cones, while those who see white and gold have eyes that "don't work well in dim light" and are more light sensitive.
Jacquot—who, for the record, sees light blue and gold—doesn't agree with this idea entirely. "Terms like 'high functioning' are relative terms and a bit subjective, and I wouldn't say that one group is better than the other," he says. But he does admit that the amount of light that enters the eye can play a role in color perception. Darkly pigmented irises let in less light than light ones, he points out, so eye color could possibly be a factor.
To sum it up, not even brain and eye experts know all the answers here. In all likelihood, the explanation is partly physical (the organization of cone cells in the eye or the retina's ability to let in light) and partly mental (the context clues our brains pick up on when we look at an object). "We can tell how someone might see black and blue or white and yellow," Lotto says, "but what we don't fully understand is exactly why one individual sees it differently than another."