Does blue light harm our eyes?
Especially when you ask the question whether blue light is harmful to the eyes, there are many different opinions. The health aspect is particularly interesting for people who work a lot at computer screens. For this, however, you have to distinguish between the effects of artificial and natural blue light radiation.
On the one hand, you are irradiated by the natural blue light component of the sun. On the other hand, the artificial blue light of your computer or smartphone display shines towards you. And on top of that, it is also contained in LED lamps and energy-saving light bulbs.
Currently, there is a scientific discussion about whether and to what extent blue light can be harmful to your eyes. However, the question arises before the answer:
What is blue light?
Blue light is part of the visible electromagnetic spectrum. If you think of it as an image, blue light is on the left edge of the color range a human can see. Light is short wavelength and very high in energy.
Basically, light is electromagnetic radiation and each color has a different wavelength. The eye can only see the color spectrum in the range of about 380 - 780 nanometers. The blue light that you see is in the blue-violet range at about 380 nanometers and extends to 500 nanometers. From here on, blue light transitions into the green spectrum.
Blue light is very high in energy, but the ratio makes all the difference. Scientists have found that the strength of blue light in electronic devices is not intense enough to cause retinal damage.
The fact is that natural sunlight outside is already about 5,000 lux strong. The value was measured in winter when the sky was overcast. In summer, it can be up to 100,000 lux. Your screen or laptop will remain below 500 lux even at very bright settings and a distance of 50 cm.
Even when children sit in front of a computer for hours playing or participating in distance learning, vision researchers have answered the question of whether blue light is dangerous with a no. At least in terms of eye damage from the blue spectral color.
Why is there more blue light in the first place?
The sun's natural blue light surrounds you all day. Before Swan invented the light bulb, people were exposed only to natural blue light from morning to night. Today it's different because we want more and more artificial brightness. The widely used modern light sources all emit a comparatively high proportion of blue light.
It doesn't make much difference whether they are LED lamps, energy-saving lamps or the displays of desktops or laptops. Due to changes in working and living conditions, people are exposed to artificial light for much longer periods of time, sometimes even into the early morning hours..
Can blue light be harmful to the eyes?
Natural ultraviolet light has been shown to have a damaging effect on the human visual organ. Scientists are still debating the extent to which blue light can damage the eyes. They hold it responsible for damage to the retina. Another condition is the so-called blue light hazard also known as Blue Light Hazard.
Some researchers are convinced that blue light is a key reason for the development of age-related degeneration of the macula, or AMD. Symptoms of this eye disease include blurred and/or distorted vision. Lines are seen crooked or bent and colors fade. However, the effects take years to appear.
Therefore it cannot be said at present with security whether the blue light can be really at which effect blue light actually a releaser of the AMD. There is no definitive substantiated proof so far.
At what dose is blue light dangerous?
The higher radiant energy of short-wave blue light compared to other light waves has an effect on the metabolism in the retinal cells. However, there is a possibility that too much blue light can damage the retina of the eyes.
At present, there are no study results that clearly prove after which radiation duration and dose a damaging effect is possible. The light source from which the blue artificial light comes also plays a role here.
The positive influences of blue light
For example, it controls your internal clock or your natural biorhythm. Scientifically, this is called the circadian system. Blue light vitalizes and keeps a person awake. For example, it suppresses the release of melatonin. It is the human sleep hormone in the body.
The blue light is also used in therapy. In a range up to 510 nanometers, it can improve mood. This effect is used in medicine to compensate for seasonal mood disorders. For this purpose, special intensely radiating lamps with blue light tubes are used.
The effects of LED or xenon car headlights
Certain wavelengths of blue light influence the perception of objects. But they can also have a psychological effect. Many drivers find the modern headlights of oncoming cars very disturbing and unpleasant.
This results in reduced vision and one can no longer assess the situation correctly. This prevents relaxed vision. The influence of the headlights on the ability to see lasts only a short time and therefore health impairments or eye damage do not play a role.
Does blue light cause sleep disorders?
For a long time, it was suspected that evening reading with electronic devices such as an e-book reader could possibly trigger sleep disorders. In the meantime, this assumption has been refuted by a study involving 167 people. Scientists had investigated the night vision settings in smartphones to see if this function had any positive or negative effect on the subjects' ability to fall asleep.
The result was no difference was found regarding sleep quality between the two groups. One had the night function turned on and the other group did not. If you absolutely must read before bed, then you should avoid using the maximum brightness level on your smartphone or tablet - this will help protect your eyes.
This is a banal recommendation, but it is a step in the direction of eye protection. Against this background, there is advice from the professional association of German ophthalmologists that consumers should not fall for misleading advertising for various protective measures such as blue light filters.
Is protection against blue light necessary?
To answer this question, you need to distinguish between natural and artificial blue light. It is indisputable that you have to protect your eyes and skin when you are outdoors. You can protect your eyes with sunglasses and photochromic glasses, and your skin with sunscreens of appropriate strength.
The recent research results prove that there is no increased risk of retina damage caused by electronic devices or various indoor light sources. LED lamps, energy saving lamps or digital displays do not harm the eyes! Advertised protective devices such as blue light filters are pure marketing measures.
Special accessories for your smartphone, computer glasses and extra contact lenses for PC work are therefore not necessary. The built-in technologies in PCs or smartphones to reduce blue light are also superfluous.
What is always useful, of course, is to take care of your eye health and protect your eyes from harmful factors.
Our tips for protecting your eyes in blue light:
• You should avoid blue light at least half an hour before going to bed
• Any bright lighting before you go to sleep is bad for your sleep.