SCIENCE

Beyond Blue-Green: The Color That Defies Description

USA, BerkeleyFri Apr 18 2025
The human eye has been around for a long time, but it turns out there's still more to see. A group of researchers in the United States made a surprising claim. They said they saw a color that no one has ever seen before. They achieved this by using lasers to stimulate specific cells in the eye. The experiment involved firing laser pulses into the eyes of five volunteers. This stimulation targeted individual cells in the retina, pushing the volunteers' perception beyond its usual limits. The color they described is a shade of blue-green, but they insist that this description doesn't do it justice. They named this new color "olo, " derived from the binary code 010, indicating that only the medium (M) cones in the eye were activated. The researchers shared an image of a turquoise square to give an idea of what olo looks like. However, they stressed that this image is just a close match. The actual color, they say, is far richer and more vivid. This is because the laser stimulation created a color that natural light cannot produce. In natural light, all three types of color-sensitive cells in the retina are stimulated to varying degrees. But with the laser, only the M cones were activated, creating a unique color experience. The human eye has three types of cones that detect different wavelengths of light. These are the long (L), medium (M), and short (S) cones. Natural light stimulates all three to different extents, creating the colors we see. But there's no natural light that stimulates only the M cones. This is what makes olo so unique. It's a color that exists outside the natural range of human vision. The researchers believe their tool, named Oz vision after the Emerald City in the L. Frank Baum books, could help answer basic questions about how the brain processes visual information. It might also have practical applications. By stimulating specific cells in the retina, researchers could learn more about color blindness or diseases that affect vision, such as retinitis pigmentosa. However, don't expect to see olo on your smartphone or TV anytime soon. This is basic science, and it's a long way from being part of everyday technology. Not everyone is convinced by the researchers' claims. Some experts argue that olo is not a new color. Instead, it's a more saturated green that can only be produced under specific conditions. They believe the work has limited value. But whether or not olo is a new color, the experiment raises interesting questions. It challenges us to think about the limits of human perception and the potential of technology to expand them.

questions

    How can we verify that the color 'olo' is truly unprecedented if it can only be experienced through laser manipulation?
    How reliable are the subjective descriptions of 'olo' given by the five individuals who experienced it?
    What are the potential risks or side effects of using laser pulses to stimulate the retina in this manner?

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