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By: Metro, United Kingdom
Most of us will be going LED mad in a few days, as we set up shop for Christmas. Fairy lights for the tree, maybe a flashing reindeer for the garden and presents including tablets, smartphones – perhaps even the coveted Doctor Who sonic screwdriver torch.
But with a recent study by Complutense University of Madrid claiming up to 99 per cent of the cells that protect the retina can be damaged by LEDs, should we reconsider our gift choices this Christmas? Hmm, maybe not quite yet.
The Spanish researchers say LEDs produce high levels of radiation in the ‘blue band’ of the light spectrum, which can cause damage over time. And with their use ever increasing, the report authors say we should be worried. ‘This problem is only going to get worse and worse,’ says the university’s Dr Celia Sanchez Ramos.
To put all this into context, you need a basic grasp of the electromagnetic spectrum. It ranges from low-frequency waves such as radio waves (eg TV signals), to microwaves (mobile phones), infrared (cable TV) and visible light. It then moves to the more dangerous, high-frequency end – from ultraviolet (sunbeds) to X-rays (used for medical images) and gamma radiation (which kills cancer cells).
‘LEDs produce light at the same frequency range as sunlight; it’s called visible light on the electromagnetic spectrum,’ says Henry Lau from the Institute of Physics. ‘Unlike sunlight, however, the light from LEDs is not intense enough to damage someone’s eyes. Only ultraviolet and higher frequencies on the electromagnetic spectrum can cause damage to cells.’
The report still managed to ruffle some feathers, though. So where has all the fuss about LEDs come from? Bobby Qureshi, London Eye Hospital consultant opthamologist, points to the test conditions used.
‘The Madrid study tested someone looking at the equivalent of a 100watt light bulb, at a distance of 12 inches for 12 hours a day,’ he says. ‘And this isn’t something a normal person would be doing.’
He says although all light is radiation, only certain frequencies can cause harm.
‘The closer you go to the UV end of the spectrum and beyond, there is potential to cause damage in the retina,’ says Qureshi. ‘The rest of the spectrum doesn’t. As the blue colour wavelength is getting close to UV, it’s perceived as being more dangerous to the retina.’
But Qureshi says there is no cause for alarm because the full light spectrum – including the blue end – exists around us all the time.
‘If you’re looking at a blue colour then it’s in the blue end of the spectrum,’ he says. ‘It stimulates the blue sensitive cells in the retina but it’s not at all damaging to the eye.’
He says the study wasn’t without value, though, because it shows damage can be caused if you experience extremely intense blue light for an extended period of time. But he says the most we will experience from LED lights is eye strain or computer vision syndrome – headaches, dizzyness, tired or sore eyes and fatigue caused by excessive screen-time.
And even with the average person now spending nine hours every day glued to a screen (including computer, TV and mobile devices, Qureshi says it would take a huge increase in use to cause any permanent retinal damage.
‘Your eyes also have a physical barrier to the spectrum of light,’ he says. ‘When light comes in, it passes through the cornea and the lens, which absorb much of the light. As we age, people develop cataracts on their lens and this is another of nature’s ways of preventing the blue end of the spectrum of light from coming into the eye.’
His analysis will come as a relief to those who snapped up one of the 234million tablets research company International Data Corporation estimated were to be sold globally this year. For them, and the rest of us already glued to our screens or stringing up the fairy lights, it would appear there’s no need to turn out the lights just yet.
For more information, visit www.londoneyehospital.com
The London Eye Hospital’s Bobby Qureshi shares his top five eye exercises to help you maintain strong, healthy vision.
- Computer users should take regular screen breaks, ideally every 30 minutes. During breaks, look to the distance or close your eyes for a few seconds in order to rest them.
- People often find their eyes dry out because they blink less at a computer. To avoid this, try blinking every time you hit the return key.
- The glands in our eyes can sometimes get blocked, which can contribute to dry eyes. To reduce this, cover your eyes with a hot flannel for a few minutes and then massage along the eye lids. Try to do this daily. Taking supplements such as good quality omega 3 oils can also help to improve tear function.
- Some people find focusing on close-up tasks difficult. This may be due to slight weaknesses in our convergence eye muscles. Hold a pen around 40cm from your nose, then slowly move it closer until you can see it double. Do this three to four times then close your eyes for a few minutes or look in the distance to rest your eyes. Try to do this exercise little and often.
- Hold some small text around 10-20cm away. It could be the page of a book or a food label, just make sure you can read it clearly. Then look at some text in the distance, maybe on a sign or the text/subtitles on the TV. Read one line of text close to you and then a line of text in the distance. Repeat this five to ten times. Once you have completed the exercise, rest your eyes for a few minutes by shutting them or looking in the distance.
Despite doubting the Madrid study’s findings, Qureshi says we should still set guidelines when using smartphones and tablets.
- Set your device to auto brightness.
- Hold your tablet or smartphone at arm’s length (or about 70cm) from your eyes.
- Make the font bigger to stop strain on the eyes.
- Only use the device for a couple of hours a day in one sitting. Then take a break and come back to it later.