Affordable home-based eye therapies may be on the horizon following a study that found staring at a deep red light for three minutes a day improved declining eyesight.
In humans around 40 years-old, retinal cells begin to age, as the cell’s mitochondria start to decline. Mitochondrial density is greatest in the retina’s photoreceptor cell, which have high energy demands. As a result, the retina ages faster than other organs, with a 70% ATP reduction over life, causing significant decline in photoreceptor function as they lack the energy to perform their normal role.
“Mitochondria have specific light absorbance characteristics influencing their performance: longer wavelengths spanning 650 – 1000nm are absorbed and improve mitochondrial performance to increase energy production,” said lead author Professor Glen Jeffery, University College of London Institute of Ophthalmology.
The retina’s photoreceptor population is formed of cones, which mediate colour vision and rods, which provide peripheral vision and adapt vision in low/dim light.
The study, published in Journals of Gerontology comprised 12 males, 12 females, aged 28-72, with no ocular disease. All were tested for rod and cone sensitivity at the study start, given a small LED torch to take home, and asked LED torch to take home, and asked to look into its 670nm light beam for three minutes a day for two weeks, before being re-tested.
Cone colour contrast sensitivity improved by up to 20% in some around 40 years and over, with more significant improvements in the blue part of the colour spectrum which is more vulnerable in ageing. Rod sensitivity also significantly improved in this group, though less than contrast.