New color seen for the first time by fooling the eyes

Five people have witnessed an intense green -blue color that has never been seen by humans before, thanks to a device that one day may enable them with a type of color blindness to experience typical vision.

We perceive color via the retina on the back of the eye, which typically contains three types of light cone cells called S, M and LL, which absorbs an intervals of blue, green or red light respectively and then sends signals to the brain. When we see something at the blue -green end of the visible spectrum, at least two types of cone cells are activated at the same time because some are some overlap in the wavelengths they detect.

Pure NG at the University of California, Berkeley, wondered what color people would perceive if only one type of cone was activated in this part of the spectrum. He was inspired by a unit called OZ, developed by other researchers who studied how the eye works, using a laser capable of stimulating individual cone cells.

NG and his colleagues, including the researchers who built OZ, upgraded the unit so that the cut delivers light to a small square patch of approx. 1000 cone cells in the retina. Stimulation of a single cone cell does not generate enough from a signal to induce color perception, says NG.

The researchers tested the upgraded version of five people who only stimulated the m -cones in this little one of one eye while the other was closed. Participants said they saw a teal color, which the researchers have called Olo, it was more intense than something they have seen before. “It’s hard to describe; it’s very brilliant,” says NG, who has also seen Olo.

To verify these results, participants took a color match test. Each seen olo and another color that they could set via a dial for any shade on the visible spectrum, it matched Olo as close as possible. They all called until it was intense tile color, supporting those who saw Olo as they described.

In another part of the experience, participants used a dial to add white light to Eith Olo or a living teal device, they matched even closer. All participants dilute Olo, which supports it is the more intense of the two shades.

Andrew Stockman at University College London describes research as “kind of fun”, but with potential medical implications. For example, one day the device could enable people with red -green color blindness who have difficulty distinguishing between these colors, to experience typical vision, he says. This is because the condition is sometimes caused by m and l -cones, both of which are activated by wavelengths of light that are very similar. Stimulating one over the other could enable people to see a wider range of nuances, though this needs to be tested in trials, says Stockman.