ICYMI: This Laser Can Make Your Eyes Perceive a Never-Before-Seen Color

Study participants described the new color as a highly saturated blue-green.

iStock/EyeEm Mobile GmbH

A new laser-powered device hijacks the human eye’s color-perceiving cells, allowing its operators to alter what their subjects see. Researchers at the University of California, Berkeley, used the technology — dubbed “Oz” in a nod to The Wizard of Oz’s technicolor world — to temporarily reprogram five people’s photoreceptors, which led them to perceive a completely novel color. They detailed their work in Science Advances. 

Colors are visible to us thanks to the interplay between the light illuminating our world and millions of light-sensitive cells populating our retinas. People with typical color vision have three distinct sets of these cells, called cones, dedicated to the three swaths of the visible light spectrum. S cones take in shorter, bluer wavelengths, M cones take in medium, greener wavelengths, and L cones take in longer, more red wavelengths. Our brains translate the information they detect into the rainbow of colors we see. 

In the natural world, no existing wave of visible light can exclusively stimulate M cones. So, the researchers used Oz’s laser to do just that. The study participants said the resulting color was unlike anything they’d seen before. They described it as a “blue-green of unprecedented saturation.” Rather than manipulating the participants’ whole field of vision, the laser worked on just a fraction of cells, resulting in a small visible square of the new color, “olo.” 

Big Picture: People with color blindness often only have two sets of fully functioning cones, which means they take in two portions of the visible light spectrum rather than three. The researchers behind Oz hope to eventually use the technology to create a third line of color which could briefly expand the visual range of people with color blindness. It’s not yet clear, however, whether or how a brain which had never previously received this visual information would interpret it, co-author and Berkeley professor of electrical engineering and computer science Ren Ng told Nature.

Read More: This Impossible New Color Is So Rare That Only Five People Have Seen It. Scientific American

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About the Author

Bella Isaacs-Thomas

Bella is the Staff Writer and Editor for BrainFacts. She previously worked as a digital science reporter at PBS NewsHour, where she was named a fellow in the 2022-2023 class of the National Science-Health-Environment Reporting Fellowships (SHERF) and earned a 2021 D.C. Science Writers Association Newsbrief Award for writing. She graduated from the University of Michigan with a bachelor's degree in 2018.