Scientists just created a never-before-seen color using laser light

A team of scientists has developed a real-life method that changes how we see color. The experts are not just enhancing what’s already there – they’re showing people a color that doesn’t naturally exist in the world around us.

A deeply vivid blue-green shade that viewers say is unlike anything they’ve ever seen.

Researchers from the University of California, Berkeley have introduced a novel method known as “Oz.”

The technique uses precise beams of laser light to activate individual photoreceptor cells in the retina, allowing them to craft a completely new visual experience.

The resulting color, which they call “olo,” has never before been seen by human eyes.

“It was like a profoundly saturated teal… the most saturated natural color was just pale by comparison,” said Austin Roorda, a professor of optometry and vision science at UC Berkeley.

Laser light and human color vision

The Oz system can target and stimulate up to 1,000 individual cone cells in the eye at once. This allows the user to see the color olo, along with shapes, lines, motion, and even recognizable images, like babies or fish, all of which are conjured up within a tiny portion of the visual field.

“We chose Oz to be the name because it was like we were going on a journey to the land of Oz to see this brilliant color that we’d never seen before,” said James Carl Fong, a doctoral student in electrical engineering and computer sciences (EECS) at UC Berkeley.

“We’ve created a system that can track, target and stimulate photoreceptor cells with such high precision that we can now answer very basic, but also very thought-provoking questions about the nature of human color vision.”

The system relies on an incredibly refined method of directing microscopic pulses of green laser light onto the retina.

These are controlled in a way that either excites or avoids specific types of photoreceptors – S, M, or L cones. It’s like painting with light, but at the scale of individual cells.

The color vision puzzle

Humans see color through three types of cone cells. S cones detect short (blue) wavelengths of light, M cones detect medium (green) ones, and L cones detect longer (red) wavelengths.

But M and L cones respond to very similar light, with their activation range overlapping by about 85 percent. That overlap makes it impossible to stimulate M cones in isolation using natural light.

“There’s no wavelength in the world that can stimulate only the M cone,” said Ren Ng, a professor at UC Berkeley. “I began wondering what it would look like if you could just stimulate all the M cone cells. Would it be like the greenest green you’ve ever seen?”

To explore this, Ng partnered with Roorda, who had already developed a technique for stimulating individual photoreceptors. Together, they expanded it to target thousands of cells, hoping it would unlock new visual experiences.

A tiny, technicolor display

The Oz project began in 2018, with Fong building the software that would translate digital images into micro-laser signals.

But before those signals could be sent, the team needed a map of a person’s retinal cone arrangement. Collaborators at the University of Washington provided just that – an optical system to image and identify each cone in the eye.

Once mapped, Oz would fire pulses only when the laser beam aligned with the intended cones. Although the laser itself is just green, activating specific combinations of S, M, and L cones allows the system to generate a full range of colors. Or, by focusing mostly on M cones, it can create olo.

“If you look at your index fingernail at arm’s length, that’s about the size of the display,” Roorda said. “But if we could, we would have filled the entire visual space like an IMAX.”

Striking new color from a laser beam

To test Oz, five participants – including Roorda and Ng – viewed the new color and compared it to other colors. They all described olo as an intense blue-green, much more saturated than anything they’d ever encountered.

“The most saturated colors you can experience in nature are the monochromatic ones. Light from a green laser pointer is one example,” Roorda said. “When I pinned olo up against other monochromatic light, I really had that ‘wow’ experience.”

Doctoral student Hannah Doyle led the experiments. She also tested what happened to the color when the laser beam was slightly “jittered,” hitting random cones instead of only M cones. Just like that, olo vanished.

“I wasn’t a subject for this paper, but I’ve seen olo since, and it’s very striking. You know you’re looking at something very blue-green,” Doyle said. “When the laser gets jittered, the normal color of the laser almost looks like yellow because the difference is so stark.”

New ways to study sight

The Oz system isn’t just a visual trick – it may offer powerful new tools for studying vision loss and color perception. Diseases that damage cone cells could be simulated with pinpoint accuracy by deactivating targeted cells in healthy participants.

“Many diseases that cause visual impairment involve lost cone cells,” Doyle said. “One application that I’m exploring now is to use this cone by cone activation to simulate cone loss in healthy subjects.”

There’s also potential for helping those with color blindness to see a broader spectrum, or even giving people tetrachromatic vision – the ability to see four primary color dimensions instead of three.

“We found that we can recreate a normal visual experience just by manipulating the cells – not by casting an image, but just by stimulating the photoreceptors. And we found that we can also expand that visual experience, which we did with olo,” Roorda said.

“It’s still a mystery whether, if you expand the signals or generate new sensory inputs, will the brain be able to make sense of them and appreciate them? And, you know, I like to believe that it can. I think that the human brain is this really remarkable organ that does a great job of making sense of inputs, existing or even new,” he concluded.

The full study was published in the journal Science Advances.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–