Eco-bulbs: making us blind? New generation energy efficient appliances and lights are destroying our sight.
Ever noticed your eyes feeling red, gritty and tired after working at the computer for a while? The race for ever-sharper definition, and more energy efficient screens, has seen the widespread adoption of LED technology over the past couple of years.
Light Emitting Diodes used to be confined to clock radios, the very first digital watches and stereos, and numerous geeky electronics projects for kids. Now, they're everywhere: in smartphone screens, tablets, iPads, TVs, computers, car dashboards.
The problem with all that, is eye strain leading to possible eventual blindness. Researchers all over the world are warning that the proliferation of LED displays everywhere is exposing us to higher and higher levels of blue light radiation on a daily basis --the kind that causes serious eye damage over time.
Blue light is found at the upper end of the UV radiation spectrum, at a wavelength between 46o-50onm. It's a by-product of LED technology, and is also an environmental pollutant from fluorescent lighting in offices and CFL 'energy efficient' lights in homes.
Normal incandescent light bulbs tend to be warmer, more yellow/orange in tone that the extreme whites verging on blue of LEDs and CFLs. Whilst the official government propaganda describes incandescent bulbs as "inefficient", that's not strictly correct. The more primitive bulb technology burns a higher proportion of its energy as heat, thus helping to heat homes and partly offset heating bills. LED and CFL lights are much colder, both in tone and in energy output, but they come with blue light baggage.
Scientists have known for some years that exposure to high intensity blue light can rapidly damage your eyes, but they didn't have hard data on the impact of low intensity household lighting. Because of ethical constraints they couldn't test the theory on humans, so laboratory rats were used for a just-published study in the Journal of Environmental Health Perspectives. (1)
To simulate household lighting, they placed a low power LED light 20cm above the floor of a rat enclosure, at such a distance from the animal so as to match the power of a household light at human eye level. Four control groups of rats using four different light sources were tested--108 rats in all.
The lights were left on for 12 hours a day, and turned off and left dark for 12 hours a day.
The rats were not strapped to a little rat bed and force to stare at the ceiling, this experiment allowed them to go about their daily business, just as we do.
Rats were examined in staggered groups--some ended after three days, some for 9 days, some for 28 days. The results were shocking. The longer it went, the worse the eyes became, and damage was apparent early in the piece.
After just nine days exposure to white LED light from either PC LEDs or domestic LED lightbulbs, there were significant signs of eye damage in the retinas. Remember, this was a test of "chronic exposure"
simulating home and office conditions using home and office light power levels.
"White LED light may induce outer retinal damage within 9 days and may be responsible for further deterioration when the exposure duration is extended," the study warns.
Of course, in the real world we live in our homes all our lives, and most of us go to work each day.
"LEDs are expected to become the primary domestic light sources in the near future. Certain amounts of LED light exposure may induce retinal damage, and this animal model provides comparative measures of damage from different commercial light sources," says the study.
The real risk, they say, is that the damage becomes greater and greater with time, and is not repairable: "Bluish-white (high CCT) LEDs contain a major fraction of short-wavelength light that causes irreversible retinal neuronal cell death ...
When analyzing blue-light hazards, we cannot exclude the risk of chronic effects from daily exposure because photochemical damage may not induce an acute syndrome; instead, blue light exposure may cumulatively induce photoreceptor loss.
"Regardless of whether the initial damage is caused by a photochemical effect, LED light damage is dependent on wavelength and duration. The entire retinal neuronal cell is affected, regardless of whether the injury is localized in the outer segment, mitochondria, or other subcellular organelles. Because illuminance levels of LED domestic light sources may induce retinal degeneration in experimental albino rats, the exact risks for the pigmented human retina require further investigation." Incandescent lights caused no such problems, and CFL mercury energysaver bulbs caused about two thirds the damage of LEDS.
That study was a test of ambient room lighting, but the question becomes grittier and even more concerning when computer, TV and phone screens are thrown into the mix. We are not using those devices to provide ambient overhead light. We are looking at the light directly, often for hours at a time.
One US opthamologist gained attention last year by sending a news briefing to clients, warning them of what the studies are now showing:
"Our eyes are our light filters. The very images we see are light reflections. It is widely understood that certain light wavelengths can cause harm to our skin and eyes when left unprotected. Hence sunscreen and UV protected sunglasses. What about the blue light that is emitted from your iMac or Android phone? Or the fluorescent lighting in your office or home? How do you protect your self from that?
"Countless studies are legitimizing the correlation between overexposure to blue light and retinal damage. One of the leading modifiable environmental risk factors associated with Age-related Macular Degeneration is prolonged, unprotected exposure to blue light. In fact, there is mounting medical evidence that prolonged exposure to blue light may permanently damage the eyes, contribute to cataracts and to the destruction of the macula. In an era dominated by office environments and gadgets emitting blue light, what can be done to protect and preserve your health and vision from its hazardous effects?"
The answer isn't pretty. The good doctor admits that it's too late to break the Facebook and iPhone addictions, and that trying to tell people to ration it would be "like screaming underwater". The only other solution is to get yellow-tinted glasses.
And not just any yellow tint, it has to block the blue light at just the right wavelength or the glasses will be useless.
Earlier this year the BBC published a survey of 2000 people and found that under-25s are checking their smartphones 32 times a day on average, or roughly every half hour they're awake.
"It also found 55% felt the amount of screen time they're exposed to affects them with eye discomfort the main problem. Eighteen-year-old Alana Chinery from Essex is never without her smart phone.
"I've definitely noticed that my eyes are getting worse from staring at my computer and phone. I am getting more headaches," she told the BBC.
The danger is that with LED technology now in the hands of children through tablets, iPads, and handheld games, and the Government looking to make sure every child has a tablet at school, eye damage is starting one to two decades earlier than it did for their parents, and during a time of crucial eye development.
They could be, warn some specialists, the first generation to be legally blind in their late fifties thanks to macular degeneration caused by retinal damage.
"Bear in mind that as the lens of the eye ages, it begins to yellow. This yellowing gives adults some, but not adequate, protection against UV-A and blue light. However, children have not lived long enough to have this yellowing. Therefore UV or blue light which enters the eye will strike the retina at full-strength exposing not only the retina, but the lens to damage," writes Elaine Kitchel, a Low Vision Research Associate with the American Printing House for the Blind.
It is, she warns, a ticking time bomb for parents:
"Often the lesions from UV-A and blue light are scattered on the retina.
It is only when enough of them appear and coalesce that one begins to notice a vision loss. This is why vision loss is not immediate, but often takes many years to manifest. This is the reason why children, especially ones who already are suffering from a vision loss, must be adequately protected."
The issue made headlines in USA Today recently:
"One day after Sarah Hinkley had been working on her computer for about five hours, she noticed her eyes started to burn and feel dry. 'My focus became blurry, like I was looking through a haze,' she says.
"As an optometrist, Hinkley knew exactly what was wrong. She was suffering from digital eye strain, also known as computer vision syndrome.
"In fact, almost 70% of U.S. adults say they have experienced some of the symptoms of digital eye strain, according to a survey conducted for the Vision Council, a trade group for vision care products and services. About 60% of respondents say they spend at least six hours looking at screens daily.
"The problem is starting to occur more frequently in kids, Hinkley says. 'As children acquire cellphones at younger ages and are using them more frequently during the day, we are seeing the symptoms presenting in younger children more than we have before.'
"The symptoms may include dry, red and irritated eyes, fatigue, eye strain, blurry vision, problems focusing, headaches, neck and shoulder pain and possibly even words moving on the screen because of underlying eye alignment issues, which are binocular vision (how the eyes work together) problems, she says. The latter is not as common as dry eyes, eye strain and blurry vision."
If you are hoping the lighting and computer industries will fix this, they won't unless sales start to be hurt. At the moment both groups are playing down the issue.
The problem is, there is currently no cure for the eye damage, the blue light is killing your retinal cells day by day and they won't come back. If you're resisting wearing yellow glasses yourself, think what your kids will say. But if someone doesn't act fast, we may not only have the biggest proportion of old people within a generation, but a massive problem with gradual blindness in the working age population at the same time.
Piece of advice? Get rid of the energy saving light bulbs, and get some yellow glasses if you are spending time watching TVs or computers.
(1.) White Light-Emitting Diodes (LEDs) at Domestic Lighting Levels and Retinal Injury in a Rat Model, Shang et al, Environ Health Perspect, Volume 122 | Issue 3 | March 2014; DOI :10.1289/ehp.1307294
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|Date:||Aug 1, 2014|
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