New research suggests that three minutes of morning exposure to deep red light can help improve declining eyesight.
The study, which was published in Scientific Reports, expands on the team's previous work, which found that daily three-minute exposure to longwave deep red light "switched on" energy-producing mitochondria cells in the human retina, aiding in the restoration of naturally deteriorating vision.
The goal of this current study was to see what effect a single three-minute exposure would have while using far lower energy levels than earlier experiments. Furthermore, the scientists contrasted morning and afternoon exposure, drawing on separate UCL study in flies that discovered mitochondria have "shifting workloads" depending on the time of day.
The findings, according to scientists, signify a breakthrough for eye health and should lead to affordable home-based eye medicines, benefiting millions of individuals worldwide with naturally failing vision.
"We demonstrate 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," lead author, Professor Glen Jeffery (UCL Institute of Ophthalmology), said.
"This simple intervention applied at the population level would significantly impact on quality of life as people age and would likely result in reduced social costs that arise from problems associated with reduced vision."
In summary, researchers discovered that three minutes of 670 nanometre (long wavelength) deep red light in the morning improved participants' color contrast vision by 17% on average, and that the effects of this single exposure lasted for at least a week. When the same test was done in the afternoon, however, there was no improvement.
The study emphasizes that morning exposure is critical for improving failing vision. Previous research has shown that mitochondria have fluctuating work patterns and do not respond to light in the afternoon in the same way, and this study backs up that theory.
The light energy emitted by the LED torch for this study was just 8mW/cm2, rather than the 40mW/cm2 that they had previously utilized. This causes the light to dim, but it has no effect on the wavelength. While all energy levels are entirely safe for the human eye, further lowering the energy is a bonus.
Various groups have also demonstrated in lab trials that illuminating a deep red or near-infrared light on the head can help animals with induced brain lesions and diseases including stroke and Parkinson's disease.
Jeffery's team also discovered that red light irradiation can protect bees from neonicotinoid insecticides, which cause mitochondrial damage. Beekeepers should install lamps in their hives, according to the group.
