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Scientists at UC Berkeley have developed a groundbreaking technique that allows humans to see a color they’ve never experienced before. This method — dubbed “Oz” — enables people to perceive a unique blue-green shade called “Olo.”
New Scientist reports that five participants successfully viewed this unprecedented color through the Oz technique. It’s a remarkable achievement in vision science that challenges our understanding of human color perception.
The research team published their findings in Science Advances, explaining that they achieved this feat by “directly controlling the human eye’s photoreceptor activity via cell-by-cell light delivery.” This highly targeted approach bypasses the natural limitations of human vision.
The researchers hope to use this technology to address color blindness issues, particularly red-green deficiencies that affect millions worldwide.
Our eyes normally perceive color through the retina’s photoreceptors — specifically three types of cone cells that detect different wavelengths of light. These S, M, and L cones (small, medium, and long) work together to create our color experience. M cones respond primarily to green light, but seeing blue-green typically requires multiple cone types to activate simultaneously.
What makes Oz revolutionary is its precision.
Using carefully calibrated laser microdoses, the Berkeley team found a way to stimulate individual M cone cells in isolation — something that doesn’t happen in natural vision. This targeted approach creates a color experience outside our normal visual range.
“Theoretically, novel colors are possible through bypassing the constraints set by the cone spectral sensitivities and activating M cone cells exclusively,” the scientists explained in their paper. “In practice, we confirm a partial expansion of colorspace toward that theoretical ideal.”
The researchers described Olo as a blue-green shade with “unprecedented saturation” — essentially a more vivid version than anything naturally visible to humans. Their system can deliver these laser microdoses to thousands of classified cone cells, even accounting for natural eye movement.
While creating a never-before-seen color is fascinating, the team is focused on the technology’s practical applications. Hannah Doyle, co-lead researcher and fourth-year PhD student in electrical engineering at Berkeley, told Gizmodo: “Showing olo is definitely cool, but we’re all looking toward the future for how we can use the technology itself.”
Doyle is already expanding the research. “I’m actually now working on a project using the same exact system to simulate cone loss, like what happens in retinal disease, in healthy subjects,” she explained.
These findings represent a proof-of-principle for programmable control over individual photoreceptors, potentially opening new frontiers in vision research and treatment options for those with visual impairments.
