Five Volunteers Witness New Colour Through Laser Experiment
Five volunteers in the United States have become the first people to see a colour that sits outside the normal bounds of human vision after researchers precisely targeted single photoreceptor cells in their eyes with laser light. The new hue, christened “Olo”, was described by participants as an extraordinarily vivid blue-green whose saturation exceeds anything found in nature or on a computer screen. Pinpointing the retina The feat relied on “Oz”, an adaptive-optics system that maps every cone cell in a patch of retina and then uses an eye-tracking laser to activate only the medium-wavelength (M) cones responsible for green perception. In normal circumstances, any light energetic enough to excite M cones also stimulates long- or short-wavelength cones, so the brain never receives a pure M-cone signal. By isolating that channel, the Berkeley and Seattle-based team elicited a pattern of neural activity the brain had never processed, leading to the appearance of a brand...