A team of scientists managed to stimulate the retina showing the human eye a new colornaturally imperceptible: they called it Oloand whoever saw it (just five people) describes it as “an incredibly saturated blue-green”. “The ultimate goal is to provide a programmable check on each photojroach of the retina”, explains James Fong, one of the authors of the research published on Science Advances. Having full control of the retina could serve in the future to study more deeply the vision of the human eye, replicating the effects of different diseases of the vision and, theoretically, managing to compensate for the damaged or missing photocercers.
Coni and sticks. The human eye has cells sensitive to light calls photocercers, which can be coneswhich perceive high light levels, or stickswhich perceive low light levels. There are three types of cones, each specialized in the identification of specific wavelengths of visible light – those called L, which perceive the long length and therefore the red light, the M, medium length and green color and the S, from shortshort length and blue color. Once activated, it is the task of the brain to interpret the signals of these cells through the retina and show us the right color.
Selective activation. THE Coni M are more sensitive to green lightbut actually respond to an entire spectrum of colors that overlaps with long and short wavelengths: for this reason, in nature, it is impossible to activate only the cones M without activating the L and S. the scholars, however, have succeeded, stimulating them mechanically with a laser light. This selective activation has allowed participants to see the OLO color, a name that refers to coordinates 0, 1, 0 on a 3D color map.
The experiments were certainly not without complications: to see the OLO color, for example, the participants had to keep their gaze fixed on a precise point, because the scientists had mapped only a small part of the retina containing hundreds of cones. Allowing the gaze to move freely would mean going to “substantial technical difficulties”, say the authors.
Daltonia and Tetracromia. Now the researchers are thinking of using this New technique not only to study and treat Daltoniabut also to stimulate the experience of having a fourth type of cone – which happens naturally in some people who have one Genetic condition called Tetracromywhich allows them to perceive more shades of color than normal.
