Are you feeling exposed?

Prolonged use of screens emitting blue light may be damaging your eyes and skin

WHEN we’re not in front of a TV or computer screen, many of us spend the day attached to our phones, checking them long after natural light has faded outside.

It’s increasingly recognised that the blue light emitted from these devices can disrupt our body clocks and sleep patterns, but now doctors warn it may also damage our skin and eyesight.

Much of the research is at an early stage, but people are urged to at least turn off their tablets, phones and computers before bed.

Here’s what emerging evidence suggests:

It might hurt eyes: Blue light, also known as high-energy visible light, is part of the visible light spectrum (red, orange, yellow, green, blue, indigo and violet). Blue to violet light has the shortest wavelength on the spectrum – the shorter the wavelength, the higher its energy.

Last year, US scientists published research suggesting that blue light might damage vision and speed up the onset of blindness. Researchers at the University of Toledo found that prolonged exposure to blue light triggers toxic molecules in the eye’s light-sensitive cells, killing them off – a process that leads to macular degeneration.

The lab-based study found that blue light triggers retinal – a protein in our eyes that senses light – to create poisonous molecules in the photoreceptor cells. There were no changes when the cells were exposed to green, yellow or red light.

Commenting on the findings, Dr Ajith Karunarathne, an assistant professor in the university’s department of chemistry and biochemistry, said: “We are being exposed to blue light continuously and the eye’s cornea and lens cannot block or reflect it. It’s no secret that blue light harms our vision by damaging the eye’s retina. Our experiments explain this and we hope this leads to therapies that slow macular degeneration.”

It may be especially harmful to look at phones, glowing with blue light, in the dark, explains Karunarathne: “(When it is dark) your pupils are so dilated that everything coming from the device gets in.”

Yet while there is no conclusive evidence that blue light from our phones could cause vision loss, it is widely recognised that spending hours in front of devices can lead to digital eye strain.

This is characterised by headaches, fatigue, blurred vision and dry eyes.

Screen use is also linked to a raised risk of dry eyes. This is because we don’t blink as much when staring at them. We normally blink 15 times a minute, but a 2013 study published in the journal Optometry and Vision Science, suggested we blink half to a third that often when on our devices. Optometrists recommend the 20-20-20 rule – look away from the screen every 20 minutes and then focus on an object 20ft (6.1m) away for 20 seconds.

Skin damage: It’s thought that blue light, like UV light, can prematurely age and damage the skin – indeed, some dermatologists believe they can spot someone who takes a lot of selfies, or identify which ear they hold their phone to, just by examining their skin.

US dermatologist Dr Zein Obagi has said: “You start to see a dull, dirty-looking texture on one side of the face.”

Dr Jean-Louis Sebagh, a Londonbased dermatologist, says he sees examples of “screen face” in his “younger patients, the selfie generation”.

Blue light can penetrate down to the dermis, the deeper layer of skin where collagen and elastin are produced, making skin thinner and more fragile, explains Dr Stefanie Williams, a London dermatologist.

Dr Andrew Birnie, a consultant dermatologist and skin cancer specialist at the William Harvey and Kent and Canterbury Hospitals, adds: “It’s been found that blue light causes a degree of increased pigmentation. In particular, it seems to affect people with olive skin and darker skin tones.

Blue light might damage skin by generating “free radicals,” says Dr Emma Wedgeworth, a consultant dermatologist. “These are very active molecules that bind to skin and cause significant cellular changes. They affect the way DNA is repaired.”

She points to any potential harm likely to be linked to the “amount of time on our phones and the fact we are holding them in direct contact with our skin”.