Only five people in the world have seen this new color. The trick: laser in the retina

It is estimated that the human being is able to see around ten million different colors, According to the American Academy of Ophthalmology. This is what we know as a visible spectrum, that is, those wavelengths to which Our eyes respond. Although there are exceptions, we all see more or less the same, but since last Friday there are five people in the world capable of seeing a color that the rest of mortals cannot see. The key: very precise laser surgery to stimulate concrete retin cells.

Context: How do we see? As we said before, our eyes see the visible spectrum, that is, the wavelengths between 380 and 750 nanometers. Below the 380 we have ultraviolet light and above 750 infrared. This is possible thanks to some cells located in our retinas called cones, photoreceptors that react to concrete wavelengths and send signals to our brain, which is responsible for processing everything:

• Cones S: short wavelengths, that is, the blue.
• Cones M: Medium wavelengths, that is, the greens.
• Cones l: long wavelengths, that is, the red ones.

S, M, L and all together. The cones do not react only to a concrete and exact wavelength, but their ranges overlap. The M cones will react to the longest blue wavelengths, as well as the S s will react to the shortest green zone lengths. According to Ren NG, Professor of Electrical Engineering and Computing Sciences of the University of California, “there is no light in the world capable of activating only Mons M. If they are activated, be sure that one or two more types will be activated too.”

The experiment. In the above is the key to the experience whose results were published last Friday in the Science Advance Magazine. What if we manage to stimulate concrete cones alone and exclusively? That was what the researchers from the University of California did: map the retina, look for cones m and excite them with small doses of light, laser. It is a technique baptized as Oz, in honor of ‘The Oz Wizard‘And the Emerald city.

This is the closest representation to the “Olo” color that can be made on a screen | Image: Xataka

OLO. After undergoing the experiment, the study participants were able to see a new color they called “Olo.” Of the five participants, three of them were co-authors of the study (the aforementioned Ren NG was among them) and two were colleagues from the University of Washington. This “Olo” is defined as “a bluish green with unprecedented saturation.” According to NG, the closest way to represent “Olo” on a screen is with the Hexadecimal #00FFCC, but with saturation that we cannot understand why, literally, our brain has never received that signal.

How to verify it? To verify that all participants saw an alien and hidden color to the rest of mortals, made chromatic correspondence experiments comparing “Olo” with a bluish green laser that saturated or unraveled by adding white light. Everyone agreed that adding white light to “Olo”, Ergo unleashing it, the color of the laser was achieved, thus confirming that “Olo” is outside the visible spectrum of the human eye.

And for what? It is an excellent question. The reality is that, for the moment, it does not have a practical utility beyond demonstrating that the procedure works. In Scientific American They collect the testimony of the principal researcher and his team, which imagines some screens capable of scanning retinas and broadcasting images and videos in impossible colors. However, it may make more sense in other lands. For example, allow the blind people to see certain colors or “simulate”, in quotes, how you see an animal in our own eyes. The problem, of course, is that the Oz effect is temporary, not permanent.

Cover image | Amanda Dalbjörn

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