Influences LED monitors on the eye

Do screens damage your eyes?

It's the same with the eyes as with any other part of the body: one only consciously perceives them when they are not working properly. If they burn and itch, if your eyesight deteriorates or the lens becomes cloudy. But our eyes are the central sensory organ: we perceive up to 80 percent of the information from our environment with them - and with our current lifestyle we expect a lot from them.

We work on the computer, look at the smartphone often and happily, and in the evening we watch TV. In short: we look at illuminated screens at close range for many hours every day. Experts speak of digital visual stress: the eyes tire, and quite a few complain of dry eyes, a phenomenon that is also known as "office eye syndrome" or "gamer eye": if you look at your PC, laptop or mobile phone with concentration, the blinking frequency drops. The result: the tear film is no longer evenly distributed over the eye and can tear open.

This article is included in Spectrum Compact, keep your eyes open! - How we see the world

But the constant view of screens could have far more unpleasant consequences: Because the displays of cell phones, tablets and the like today mainly use light-emitting diodes (LED) for backlighting. And these mix to create white light, especially yellow and blue light. "There are increasing signs that blue light could be harmful to the eye," says ophthalmologist Peter Heilig from the University of Vienna.

"There are increasing signs that blue light could be harmful to the eye."
(Peter Heilig)

Compared to conventional light bulbs, LEDs consume significantly less energy, which is why they are not only used in screens, but also in lamps, advertising posters and headlights: ┬╗LEDs are hell in traffic: headlights are glistening brightly today, people complain, themselves Cyclists blind each other, "says Heilig, who takes a critical view of the ubiquitous use of LEDs:" Blue light glares more, distracts more and makes no significant contribution to central vision. "But is it therefore harmful to the eyes?

The light that hits and in our eyes is divided into visible light - between a wavelength of 380 and 780 nanometers - and invisible radiation in the ultraviolet and infrared range. The spectrum of sunlight is evenly distributed over the entire wavelength range. The spectrum of LEDs, on the other hand, has a clear hump in the blue range of 400 to 480 nanometers: this light is rich in energy and - unlike UV light, which is absorbed in the anterior eye area - penetrates the retina almost unfiltered through the eye. Due to the widespread use of LEDs, their different spectral light composition and our changed visual behavior, we are more exposed to blue light than before.

Does blue light harm the retina?

Studies on the effects of blue light on the eyes are undisputed: "Experimental approaches have shown that blue light - in contrast to green, for example - can cause severe damage to the retina and visual cells," says retinal researcher Christian Grimm from the university Zurich. High-energy light leads to photo-oxidative stress, which means that oxygen radicals are created that can damage proteins and lipids and ultimately lead to the death of visual cells. Damage that cannot be repaired, because dead photoreceptor cells are no longer replaced, which means that vision deteriorates. "How much blue light is necessary to cause damage is not clearly defined," says Grimm.