We’ve heard about blue light wavelengths that are emitted from screens and learned that avoiding blue light can save eyesight and regulate circadian rhythms. Blue light can be used to help stimulate the natural circadian rhythms in patients with dementia, but it’s true that it’s harmful to the eye at the high doses to which we are exposed in our technological world. Red light, on the other hand, could be an answer to improve eyesight that’s already fading.
Researchers from the University College London conducted the first experiment with people and red light. Previous studies were conducted in animals and found significant benefits from exposing the eye to a deep red light. Red light wavelengths are about 670 nm.
The improvements in sight were seen as a result of exposure to deep red-light wavelengths that specifically influence the retina’s mitochondria. Mitochondria declines with age; and because the retina has the highest concentration of mitochondria within its photoreceptor cells, the retina ages faster than any other component of the human body.
The mitochondria is responsive to long wavelength light (about 650-1000 nm) and are stimulated to produce more ATP (the cellular building blocks of energy). Within the retina are two structures, cones (color) and rods (peripheral vision). The rods are responsible for adjusting vision during dim light.
The study was conducted with healthy adults. The participants’ rod and cones were tested for respective sensitivity before the beginning of the study. They then went home with an LED light which shone deep red light and were asked to look directly into it for 3 minutes daily. After the end of the 2 weeks, the participants returned and took the same sensitivity test.
The adults who were over 40 years (who would have already begun experiencing loss of retinal function due to the declining mitochondria) had the most significant improvements. The ability to detect colors increased by 20%, and the ability to see in dimmer light improved.
The mitochondria was recharged by the light and appeared to be regenerated in adults who had declining eyesight. For those participants younger than 40, no real gains were made; but for a quick way to recharge eyesight in middle age, it’s time to ditch the blue light for the red.
Glen Jeffery, Magella Neveu, Victor Chong, Chris Hogg, Sobha Sivaprasad, Manjot Grewal, Harpreet Shinhmar. Optically improved mitochondrial function redeems aged human visual decline. The Journals of Gerontology: Series A, 2020; DOI: 10.1093/gerona/glaa155