A £12 small LED torch that emits red light could vastly improve failing eyesight, a groundbreaking British study found. 

Staring into its deep red light beam for three minutes a day for two weeks “significantly” improved participants’ vision, according to the first research of its kind in humans.

The discovery by researchers at University College London could signal the dawn of affordable home-based eye therapies, helping millions of people globally with ageing vision.

Welcoming the findings, lead author Professor Glen Jeffery, at UCL’s Institute of Ophthalmology, said: “Our study shows it is possible to significantly improve vision that has declined in aged individuals using simple brief exposures to light wavelengths that recharge the energy system that has declined in the retina cells, rather like recharging a battery.

“The technology is simple and very safe, using a deep red light of a specific wavelength, that is absorbed by mitochondria in the retina that supply energy for cellular function.”

There are about 12 million people aged over 65 in the UK, but this number will jump to around 20m in 50 years, all of whom will suffer some visual decline because of retinal ageing.

Mr Jeffery said: “As you age your visual system declines significantly, particularly once over 40.

“Your retinal sensitivity and your colour vision are both gradually undermined, and with an ageing population, this is an increasingly important issue.

“To try to stem or reverse this decline, we sought to reboot the retina’s ageing cells with short bursts of longwave light.”

In humans who are around 40 years old, cells in the eye’s retina begin to age. The pace of this ageing is partly caused when the cell’s mitochondria starts to decline.

The mitochondria are crucial to vision because they produce a type of energy called ATP to boost cell function. 

Mitochondria are at their most dense in the retina’s photoreceptor cells, which have high energy demands. 

The retina, therefore, ages faster than other organs, as it loses some 70 per cent of its energy source during a lifetime.

This leads to a major decline in eyesight, the researchers explained. 

Building on their previous findings in mice, bumblebees and fruit flies, they finally turned to the human eye in their latest work. 

By firing bursts of deep red, long wavelength light into human eyes, the performance of the retina’s light-absorbing photoreceptors improved considerably. 

Mr Jeffery said: “Mitochondria have specific light absorbance characteristics influencing their performance: longer wavelengths spanning 650 to 1000nm are absorbed and improve mitochondrial performance to increase energy production.”
The retina’s photoreceptors mediate colour vision, provide peripheral vision and adapt vision in dim light conditions.

In the study, published in the Journals of Gerontology, the team recruited 12 men and 12 women, aged between 28 and 72, who did not suffer from eye disease.

At the start of the study all participants’ eyes were tested for the sensitivity of their photoreceptor rods, which deal with low light vision, and cones, which adapt the eyes to brighter light.

The recruits were then given a small LED torch to take home and were asked to look into its deep red 670nm light beam for three minutes a day for two weeks. 
They were then re-tested for their rod and cone sensitivity.

Researchers found the light had no impact in younger individuals.

However, it “significantly improved” light sensitivity in those around 40 years and over.

The ability to detect colours improved by up to one-fifth in some participants in the 40-plus category.

This was especially the case in the blue spectrum which is more vulnerable to ageing.

Vision in low light, or “rod sensitivity”, also improved significantly for those of a similar age.

However, the progress was less notable compared to the boosts in colour detection.