A brand new color created by steering human eyes laser

Five people were able to notice the color that human eyes had never seen before, after researchers used lasers and following the technology to selectively activate certain cells in their retina. The blue-green shade has an intensity, or ‘saturation’, beyond the natural range of colors seen by humans.

The work is “technically amazing” and “extraordinary achievement,” says Kimberly Jameson, a color scientist at the University of California, Irvina.

This is not the first time the researchers have encouraged individual conical cells – photo -records in the eye whose signalizes have been interpreting the brain as a color. But this time it was done in the area large enough to change the vision of a person significantly. “What is new in this study is evidence that such new colors can actually be spotted,” says Sérgio Nascimento, a physicist specializing in a human vision at Minho University in Braga, Portugal.

Intensively

Researchers, who have published details about the technique in Progress of science April 18¹Call otherwise an inaccessible ‘olo’ color. It’s something like peacock blue or teal, “but saturation level is out of plates,” says Ren NG, a computer scientist and researcher of Vida from the University of California, Berkeley, who is also a co -author of the study and one of the test participants.

Method – called Oz and manages a software called Wizard – acts controlling precise doses of light delivered to each cell in Mrežnica, to skip signals that the brain uses to interpret the color or to create signals that he has never experienced before.

NG says the technique can create other new colors. This could also allow people with color blindness, for which there are no effective treatments, to notice the differences in shades that would not otherwise not, he says.

That would take a lot of work. So far, the team can carefully control the color in the small area of ​​vision only – about twice as much as the diameter for which the moon is covered in the sky – and the method requires technology available very few laboratory. But even if this is not applied wide, the study is “an impressive technical achievement,” says Jenny Bosten, a visual neuroscientist at the University of Sussex in Brighton, UK. “There is a lot of potential for future research using the technique.”

Fingerprints of light

Human nodius comes from the brain by comparing the signals it receives from three types of conical cone. Each is sensitive to a different but overlapping wavelength range. In shorter, blue wavelengths, the cone is the most controversial, while the M or medium of the cone is the most activated by greenish light. L cone is insensitive from the rest to red light longer wavelengths. Each color that people can see comes to the brain as a characteristic level of activation of these three cells, an analog fingerprint or a set of coordinates.

Because the m cone is in the middle of the spectrum, the light that activates it always activates adjacent to or L cones. NG and his colleagues wondered if, if the m Konus was stimulated by himself, he would create a new color.

The team first copied the retina of each trial participant, marking the position and type of each cell, using the technique developed by co -authors based at the University of Washington in Seattlu². This allowed them to monitor each person’s eye movement and train laser light on individual conical cells.

They then encouraged only m conuse microdoses of laser light. In order to test what the participants saw, the team asked them to match the color they noticed with examples of light of a wavelength. There was no match-it seems that the olo color was more intense than even the most vocational blue-green color in normal vision. Participants had to ‘wash’ Olo by adding white light to match the closest natural color, NG says.