Check out these two shots.
The one on the left represents "normal" colour reproduction: it's what our digital camera "sees" when it takes a picture, and it's what most people see when they look at the world.
On the right is the same image as it might appear to someone with protanopia - a form of colour blindness.
The condition affects quite a few people. According to recent research, about 8 per cent of men and 0.5 per cent of women in the U.S. have some degree of colour blindness.
But for those who don't, it can be hard to imagine how it affects vision. Enter The Colour Blindness Simulator, a site that offers a simulation of how colour blind people see the world.
Here's how another type of colour blindness, deuteranopia, affects people's vision, according to the site:
As you can see, a lot of the colours in that suave sweater just don't come across for someone with colour blindness (although that might be a blessing).
Protanopia and deuteranopia are relatively more common forms of colour blindness. There's also another, more rare type called tritanopia. It occurs in an estimated 0.003 per cent of all men and women. This is what that might look like:
So apparently, this is what colour blindness looks like. So far, no one has come up with a way to treat or cure the condition.
But these glasses might offer a solution for some people.
The researchers, Mark Changizi and Tim Barber, didn't actually set out to cure colour blindness, although they suspected it could be a side benefit of their work.
Instead, the team was looking for a way to help people perceive emotions and physical cues more easily. According to Changizi, the ability to see colours is evolutionarily related to the ability to understand other people's feelings.
"Most mammals - your dog, horse, bunny - have two dimensions of colour," he told io9, "a yellow-blue dimension, and a grayscale (or brightness) dimension. Some of us primates, however, have an extra dimension of colour vision: the red-green dimension."
Why the extra colours? Changizi says our red-green vision emerged "to sense the blushes and other signals we display on our faces, rumps and genitalia."
Unlike most (furry or hairy) mammals, human beings tend to have a lot of exposed skin in those areas, meaning we can see changes in the blood running under the skin.
Changizi's theory is that our colour sensing came about so we could more easily understand the changes in other humans moods and emotional states.
The glasses, which were developed along with theoretical computer scientist Barber, use a filter technology that amplifies the eye's ability to see blood under the skin.
Colour blindness is usually caused by damage to one or more retinal cones. For people who experience red-green colour blindness and whose cones are damaged but not missing, the glasses are said to improve colour vision.