Staring at a deep red light for just three minutes can drastically restore declining eyesight, according to a new study in the journal Scientific Reports. Impressively, improvements from a single session of light exposure lasted for a whole week, although the treatment is only effective if administered in the morning.
The researchers explain that eyesight tends to decline with age as the mitochondria in our photoreceptor cells begin to deteriorate, becoming less efficient at generating energy in the form of a molecule called adenosine triphosphate (ATP). However, previous research has indicated that mitochondrial performance can be boosted by long-wave light, which has a deep red color, and that exposure to these wavelengths may therefore restore function in these cells.
The retina contains two different types of photoreceptor cells: rods and cones. Rods help us see in low light, but can die over time if their energy demands are not met, while cones endow us with color vision. Importantly, cones do not die if they don’t receive enough ATP, but merely decline in function, meaning that enhancing mitochondrial efficiency is likely to restore eyesight.
Last year, the same researchers published a study revealing that three minutes of daily exposure to deep red light over a period of two weeks improves color vision of people over the age of 40 by 22 percent. In their latest study, they sought to determine whether a single exposure can generate similar benefits.
They recruited 20 participants between the ages of 34 and 70, each spending three minutes staring at a deep red light with a wavelength of 670 nanometers. Because previous research has indicated that mitochondrial function fluctuates throughout the day, the authors insisted that participants conduct their light treatment in the morning, between 8 and 9 AM.
Three hours later, the researchers tested the eyesight of each participant, finding that a single exposure to deep red light enhanced color vision by an average of 17 percent. In some older subjects, the degree of improvement was over 20 percent.
The study authors conducted follow-up tests on half of their volunteers seven days later, and discovered that these benefits were sustained for a full week. However, when the experiment was repeated using deep red light exposure in the afternoon, no improvements in color vision were observed.
Commenting on these findings, study author Glen Jeffery explained in a statement that “one single exposure to long wave deep red light in the morning can significantly improve declining vision, which is a major health and wellbeing issue, affecting millions of people globally.
“In the near future, a once a week three-minute exposure to deep red light could be done while making a coffee, or on the commute listening to a podcast, and such a simple addition could transform eye care and vision around the world.”