Since humans have been using computers, smartphones, tablets and LED lamps, we have been increasingly exposing ourselves to blue light. Light-emitting diodes (LEDs) are installed in all of these devices, which brighten monitors and displays. The LEDs are energy efficient, durable, compact – but they can emit a high proportion of blue light. It consists of short-wave and high-energy light waves that also occur in nature in the midday sunlight and keep you awake. Does this blue light damage eyes and interfere with sleep?
US researchers sound the alarm, EU appeases
In the summer of 2018, an article by the US University of Toledo in the specialist magazine caused concern Scientific Reports for attention. Researchers claimed that the blue component in the light from displays and monitors could damage the eyes badly. It can lead to macular degeneration and, in the worst case, even blindness. The blue light stimulates the cells of the eye to produce harmful molecules.
The scientific committee of the EU for health At the same time, he said on his website: “Studies show that the radiation from LED screens in televisions, laptops, mobile phones, tablets and toys is less than 10 percent of the maximum safety limit”. In normal use there would be no risk.
Small children are more sensitive
However, small children and old people can react more sensitively to the blue light, the EU experts also concede. It might blind you. Some people report flickering in front of their eyes from blue light.
Eye damage possible due to excess
“Currently there are only studies on models and animals, but not on humans,” says Professor Stephan Degle, summarizing the study situation. He is researching the Ernst Abbe University Jena including light and lighting in optics and optometry. It cannot be ruled out that the retina and the lens of the human eye can be damaged by an excess of blue light – especially if it hits the eye in a bundle, as is the case with some LED lights.
problems falling asleep
The effect of blue light on sleep has also not yet been fully researched. What is certain is that the proportion of blue light in natural evening light is only small – a signal for the body to produce the hormone melatonin, which makes you tired. Numerous studies – including from the Harvard Medical School – point out that too much blue light can inhibit the body from releasing the sleep hormone. This can lead to problems falling asleep or staying asleep. The EU’s scientific committee warns that even the activity itself – for example watching a film – keeps some people from sleeping.
Tipp: In our Sleep Disorders special, we have summarized findings from sleep research that can help you sleep better again.
Hardly any data on the intensity of the blue light
‘It cannot be said that certain types of electronic devices or certain models emit more blue light than others,’ says Professor Degle. A layman cannot see the blue light component of a device or an LED. “Unfortunately, there is also no labeling requirement for the spectral distribution of the emitted light,” says Degle.