1 - What exactly is blue light?
The subject of light is much more complicated than it looks. Everything we see is the result of many rays of light that hit our eyes and have different effects. Every light from the light bulb to the sun consists of light rays with different effects.
Light is made up of visible and invisible ultraviolet rays. These have different colors and different amounts of energy. As with the rainbow, there are red, orange, yellow, green and blue rays of light with a lot of gradations. The combination of all of this is white light, i.e. sunlight. Colors are created by vibrations of light at different wavelengths. Colors at the red end of the spectrum have high wavelengths and therefore less energy because they have to travel longer. Colors at the blue end of the spectrum have shorter wavelengths and hit the eye with more energy. So much for basic physics.
Blue-violet light is a high energy visible light classified as HEV. This proportion is most similar to the potentially harmful light from the sun. The sun is constantly producing tons of blue light and we are surrounded by it every day. In fact, even average light bulbs can give off blue light in rooms. The largest producer of blue light, the sun, emits huge amounts of blue light.
2 - Why is blue light bad?
Blue light is not bad in itself; it has both benefits and dangers. The dose makes the poison. Mainly blue light comes from the sun to the earth. When we are outside, we expose ourselves to the light immediately. It becomes more difficult with the amount of artificial light that generates blue light such as televisions and LED lighting or fluorescent tubes.
The amount of blue light that devices and artificial light emit is much less and much weaker than that of the sun. On average, however, we humans spend most of our time in rooms with artificial light and constantly use one form of screen. On the one hand, they have very low exposure and, on the other hand, they also have proportions of blue light that add up. That is why we opticians and ophthalmologists give a lot of thought to how we can maintain the health of our eyes in the long term.
3 - What does blue light do?
Blue light signals to the body that it should be alert and focused. That means exertion: for the eyes, the brain and therefore the whole body. We keep him from getting tired while reading innocently and looking at the screen. With that, in turn, one cannot calmly relax. In a blue light filter, the lenses are constructed in such a way that they reduce the exposure to digital light on the eyes and thus reduce the subsequent disturbances in the circadian cycle when sleeping. If this phase of sleep is disrupted in rhythm, the entire well-being of the person is impaired.
It is believed that adults spend up to 11 hours a day on some screen these days. Either way, our eyes are heavily stressed by digital lighting. Clearly, complications to the eye are not caused by blue electronic light, but they can contribute to visual problems.
4 - Does blue light also have advantages?
Yes, if you want to stay awake. Aside from that, high energy blue light is what makes the sky blue. Because blue light is more easily scattered than other visible light rays when they hit the air and water in the atmosphere. A cloudless sky is immediately colored blue. Basically it is completely scattered blue light.
5 - How does the eye perceive blue light?
The eye can do a lot, but not everything. A human eye has the front cornea and lens, which are quite effective at blocking UV rays from hitting the retina. It is very sensitive to light, for example, even without sunglasses, little UV radiation comes into your eye and causes less damage. But we wear the sunglasses to support the eye because they filter 100% of the UV radiation and help us avoid cataracts, snow blindness, pinguecula or even potentially cancer.
The eye is not at all equipped against blue light. The entire amount practically comes through the cornea and hits the retina. If our eyes are constantly and strongly exposed to blue light, long-term damage to the retina is assumed. The effects of blue light on the eyes have not been researched for long because we humans haven't let so much blue light hit their eyes for that long. There are indications that many changes can be caused by constant and prolonged exposure to blue light, such as macular degeneration, which in turn can mean permanent loss of vision.
How much blue light is too much is not yet entirely clear. But so much natural and artificial blue light is likely to mean a high risk for our eyes in old age. Avoiding it is also very easy.
6 - How does a blue light filter work?
Blue light filters block some of the blue light with a special coating. It manages to reflect the blue light and divert it from the eye. The percentage of blocked light depends on the type of coating.
Blue light filters have clear and yellowish tones. At first sight you don't see the difference either. You can only notice it when you put on the glasses yourself. The tendency is that yellow glasses can filter more of the blue light than their more transparent counterparts.
7 - What are the advantages of blue light filters?
There are two potential benefits: it reduces eye strain and you sleep better. Or you fall asleep more easily and get into the restful phases of sleep. Whenever we use digital devices, our brain registers that it is being used with the whole body. Maybe we still want to work or move. There is research showing that blue light filter wearers have more restful and consistent sleep around three to four hours before bed.
We already know that much. Exactly how the use of blue light filters affects the eyes or what consequences it has on eye health in the long term has not yet been researched. These types of filters are still too new to use for this. It is also our negative habits, such as constantly looking at a display for several hours a day. This logic alone speaks for the advantages of glasses with a blue light filter.
8 - Will the blue light filter bother me?
Blue light is easily scattered due to its wavelengths. As a result, it is not as focused as other light. If we stare at a display for a long time, we cannot always see the entire screen clearly. Our eyes perceive a large part of the screen as blurred noise. The contrast to other colors and shapes is reduced and large amounts of blue light can enter and strain the eye.
It is more likely that the eye is relieved and seeing is generally more pleasant and concentration is easier as a result. Based on scientific findings in optics, we know that lenses block the wavelengths of less than 450 nm blue-violet light, actually enabling higher-contrast vision. Usually the lenses are more yellowish or tinted yellow. Designers, photographers or artists often have concerns here that the perception of the colors could deceive them. Probably the work will also be easier for them with a blue light filter, because you stay focused longer. If you then want to be absolutely sure, you simply take off the glasses again to adjust the color. This is also possible with blue light glasses. We are always happy to tell you how you usually protect your eyes at work or during seemingly endless hours in front of the screen.
9 - Do I need glasses with a blue light filter?
Maybe it is suitable for you and makes your vision and sleep better. To do this, we would have to talk more about your eye health and eyesight. Let's think about it: Do your eyes often get tired or do you have trouble falling asleep? Do you use a display often and for a long time at work and in your free time? Then it can't hurt to try blue light filter glasses.
At best, you'll sleep better and feel healthy. At least it takes the strain off your eyes. Some people could no longer work without it. Of course, it may be that you don't notice any difference to yourself and you don't care. But then you at least tried it, because the huge potential advantages speak clearly in favor of the blue-light glasses.
At Hestasi, we are currently offering Free Blue Light Blocking Glasses which is a great way to see if Blue Light glasses are something for you. Order you pair of free Blue Light glasses, cover shipping and get high-quality frames delivered right to your door step. As of writing this article the promotion is still active, but we will not be giving away our glasses forever!