A century old mystery solved

Technion Researchers Discovered how Retinal Structure Improves our Vision Acuity

Technion researchers were able to solve a mystery which troubled scientists and medical doctors for more than a century, and found how the retinal structure aids in improving our vision acuity. In a scientific paper to be published in the journal Physical Review Letters they describe an optical model of the retina which they constructed in the computer and through which they passed light.

“Our eyes are built like a digital camera”, explains Dr Erez Ribak from the department of physics, who solved the problem with his graduate student, Amichai Labin. “The lens comes in front, and the detector – the retina – at the back. At the far side of the retina lie the detecting photoreceptor cells, strangely covered with transparent layers of neurons. The neurons serve as wiring that process and pass the detected image to the brain, but also distort the same image. It is not clear why this wiring is not behind the detector cells, and why this feature is common to all vertebrates. This issue has mystified people since the structure and function of the eye was exposed in the late nineteenth century. Then three years ago it was found that glial (Muller) cells, which intersect the retina across the neural layers, are able to transmit light.  We constructed an optical model of the retina, and passed light through this volume. They found out that only light which came through the center of the pupil was captured in the glial cells and guided directly to the photoreceptors. Light leaking from the neighboring cells or coming from the periphery, which would clutter our sight, was rejected and scattered away. This feat could not be achieved if the photoreceptor cells came before the neural layers.”