A Precisely Pointed Laser Allows People To See New Color ‘Olo’

Researchers isolated one kind of cone in the eye and aimed lasers at it to allow subjects to see a super vibrant teal shade they call “olo.”

Think about the colors of the world around you—the blue of a cloudless sky, the green of a new leaf, the blazing red of a tulip’s petals. We see these colors because of the way our eyes work. But what if we could change how our eyes respond to light, and present them with light in a form they’d never encounter in the natural world? What would we see?

This week, researchers reported in the journal Science Advances that by using precisely aimed laser light, they were able to selectively target just one of the three types of color-sensing cones in the human retina. The cone, dubbed “M” because it responds to medium wavelengths of light, is normally stimulated at the same time as cones that respond to longer wavelength reddish light, or shorter wavelength bluish light. But after mapping the location of the cones in several subjects’ eyes, the researchers were able to target just the M cones with one specific wavelength of green laser light—a condition that would never exist in nature. The result, they say, is a highly saturated bluish-green teal color unlike anything in the real world. The researchers named their new color “olo.”

Study author James Fong, a computer science PhD student at University of California Berkeley, and his advisor, Dr. Ren Ng, join Host Flora Lichtman to talk about the project, and the possibility of expanding the limits of human color perception.

Transcript for this story will be available after the show airs on sciencefriday.com.

Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.