Retina as the New Screen: Scientists program individual photoreceptors to reveal ‘olo,’ a color beyond human vision

Researchers at the University of California, Berkeley, have taken the first step toward turning the human retina into the world’s smallest, fastest “display screen,” directly controlling individual photoreceptor cells to create imagery — including a brand‑new color called “olo” — that has never existed in natural human vision.

Dubbed the Oz system, this prototype uses adaptive optics and laser microdoses to stimulate specific cones on the retina, bypassing the usual constraints of cone‑spectral overlap.

At the heart of Oz is the principle of spatial metamerism: instead of mixing different wavelengths of light to trick the brain into seeing colors, researchers shape where light lands on the retina. By mapping each person’s unique layout of long (L), medium (M) and short (S) wavelength cones via optical coherence tomography, the system delivers thousands of micro‑bursts of laser light per second, precisely targeting only the intended cones — even as the eye jiggles involuntarily.

In formal color‑matching tests, when Oz exclusively activated M cones with a 543‑nm laser beam, participants reported seeing olo — a vividly saturated blue‑green hue that lies entirely outside the natural human color gamut. To match it, observers had to desaturate olo with added white light, proving its novelty beyond any spectrally mixed light humans can otherwise perceive.

Most news outlets have zeroed in on the wonder of this “new” color and speculated on medical uses — such as simulating color blindness or probing retinal diseases — but few have considered what Oz means for the future of immersive displays and brain‑computer interfaces. By effectively treating the retina as a high‑resolution pixel array, Oz could one day enable:

• Ultra‑portable augmented reality, where digital overlays are delivered directly to photoreceptors without bulky headsets.
  
• High‑bandwidth neural input, using the eye’s existing wiring to stream data — alerts, navigation cues or even non‑visual information — straight into visual processing centers.
  
• Customizable vision enhancement, potentially granting wearers private visual channels or alerts invisible to others, with applications in security, accessibility and specialized professions.

Real‑world deployment remains distant: current experiments require a fixed gaze point, peripheral viewing and complex lasers and adaptive optics that won’t fit into consumer devices anytime soon. Yet Oz’s proof of principle heralds a new era where the boundary between digital screens and human vision blurs — and where biology itself becomes a programmable display. As researchers refine the system to cover central vision and handle rapid eye movements, the retina could evolve from a passive sensor into a direct portal for next‑generation visual and sensory experiences.

The study, titled “Novel color via stimulation of individual photoreceptors at population scale” (DOI: 10.1126/sciadv.adu1052), by James Fong, Hannah K. Doyle, Congli Wang, Alexandra E. Boehm, Sofie R. Herbeck, Vimal Prabhu Pandiyan, Brian P. Schmidt, Pavan Tiruveedhula, John E. Vanston, William S. Tuten, Ramkumar Sabesan, Austin Roorda and Ren Ng, is published in the journal Science Advances, with the copyright notice stating: “Copyright © 2025 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY) https://creativecommons.org/licenses/by/4.0/. This is an open-access article distributed under the terms of the Creative Commons Attribution license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.”

Featured image is an AI-rendered representation of a human being possibly seeing something they had never seen.