Olo is the name of a color that, so far, has only been seen by a handful of scientists. The UC Berkeley researchers fired laser pulses into their eyes to energize specific retinal cells. The technique expanded visual perception to reveal a kind "blue-green" hue that they've named olo. It is similar to the above but not quite.
"There is no way to convey that colour in an article or on a monitor," said vision scientist Austin Roorda. "The whole point is that this is not the colour we see, it's just not. The colour we see is a version of it, but it absolutely pales by comparison with the experience of olo."
To see it, you need to subject your retina to the laser manipulation. The technique, dubbed Oz, could eventually deepen our understanding of visual perception.
Our eyes have three types of cones tuned to long, medium, and short wavelengths—basically red, green, and blue ranges. Natural light mixes all these wavelengths, triggering the cones in different ways so we see color. Red light stimulates the long-wavelength cones most, blue hits the short ones—but no natural light naturally targets the medium ones on their own.
From The Guardian:
The Berkeley team set out to overcome the limitation. They began by mapping a small part of a person's retina to pinpoint the positions of their M cones. A laser is then used to scan the retina. When it comes to an M cone, after adjusting for movement of the eye, it fires a tiny pulse of light to stimulate the cell, before moving on to the next cone.
The result, published in Science Advances, is a patch of colour in the field of vision about twice the size of a full moon. The colour is beyond the natural range of the naked eye because the M cones are stimulated almost exclusively, a state natural light cannot achieve. The name olo comes from the binary 010, indicating that of the L, M and S cones, only the M cones are switched on.
Previously:
• Optography: retrieving a dead person's last sight from their retina
