Is it possible to counteract age-related decline in eyesight and improve the vision of contrasts, details and colors? It seems so, thanks to a powerful ally, dark red light! This emerges from a very recent scientific research published in the Scientific Reports journal of the Nature group thanks to the work of a team of scientists from University College London (Shinhmar et al, Sci Rep, Nov 2021).
The decline of eyesight already occurs from the age of 40
Mitochondria are the organelles involved in cellular respiration with which they produce energy for the cell. However, with age, mitochondrial membranes undergo decline with a consequent reduction in energy production. Cellular decline is accelerated, following the aging process, by the production of pro-inflammatory free radicals. The photoreceptors of the retina, divided into cones, responsible for daytime and detailed vision, and rods, responsible for vision in low light conditions, have the highest density of mitochondria and age quickly. Scientists estimate that this aging process begins as early as the age of 40. As a consequence, 30% of the rods are destined to die progressively. As for the cones, however, these do not die but gradually lose their functionality. If, thanks to artificial lighting, it is rare to find yourself having to see in the dark and resort to the functionality of the rods, it is instead essential to maintain the health of the cones and regenerate them. But is this possible?
How dark red light can regenerate the photoreceptors of the retina, the experiment
The answer to this question is yes, it is possible. And this happens thanks to the intervention of a particular type of light, the dark red light. The researchers recruited 20 volunteers, aged 34 to 70, in good health and without eye disease. The volunteers were equipped with a torch with nine LED bulbs that emitted dark red light at 670 nm. Study participants were asked to expose their eyes for 3 minutes to this light in the morning upon waking up. Subsequently, the volunteers were exposed to tests to evaluate vision. What emerged was that up to a week after exposure to light, the volunteers showed an average improvement in vision of 17% in the perception of colors and contrasts. In older people, the improvement was estimated at 20%. The explanation provided was that the LED light recharged the photoreceptors with energy and thus regenerated the cones, a bit like the mechanism that is observed when recharging a battery. Subsequently, the test was repeated changing the time of day at which the eyes were exposed to light, namely at noon. Surprisingly, the same benefits were not observed in this case. It is believed that this difference is due to the fact that, during the day, the mitochondria produce energy in a different way and that exposure to light must respect this process.
The study is small, in fact it involved only 20 people. However, it is of considerable importance and, as the authors of the study themselves wish, it is possible, thanks to this research, that in a short time torches such as those used in the experiment could be available to the general public, with a very low price but with important benefits for eyesight.