▷ Blue light: what is it, where is it and the usefulness of a blue light filter

Increasingly, work takes us many hours in front of a computer screen, and there is a component called blue light that is harmful to our eyesight. Fortunately, many of today's equipment have blue light filters. Have you heard of them or blue light? Well, this is what we will try to explain in this new post, something that will be of great interest to you if you use a screen to work.

Index of contents

Before getting into the subject of blue light, it is worth explaining how the visible spectrum of human beings is distributed.

The visible spectrum and electromagnetic waves

Light is basically transported by an electromagnetic wave, it is energy transported through waves in space and they are always characterized by two basic elements:

• Frequency: it is measured in cycles per second (Hz) and is the number of oscillations per second that a point located in a wave performs. Wavelength: This concept is related to the previous one, and is the distance traveled by an oscillation per unit of time.

The higher the frequency, the shorter the wavelength, and this directly translates into more energy. On Earth there are many types of electromagnetic waves and all of them have these two different characteristics, in addition to others that are not of interest to us on this topic. We call this range of waves of different lengths and frequencies electromagnetic spectrum.

It is at this point that we can define the visible spectrum, which consists of a region of the electromagnetic spectrum that the human eye is able to perceive. This type of electromagnetic radiation has a wavelength that our eyes are capable of transforming into visible light and colors by affecting objects around us by refraction and reflection.

The spectrum visible to the human eye is in a wavelength range of 390 to 750 nm (nanometers), and we call it visible light. Surely you will hear infrared rays, which have wavelengths greater than 750 nm, and also ultraviolet rays, which have wavelengths shorter than 400 mm and carry high loads of energy harmful to humans.

What is blue light and where do we find it?

Depending on the wavelength of the light, our eyes will transform it into a certain color, thus forming all the colors that we are able to see. These colors range from red (longer wavelength) to violet (shorter wavelength), you can imagine why the names infrared and ultra violet.

Well, blue light occupies a range within the spectrum of visible light that occupies wavelengths between approximately 400 and 495 nm, so we must know that it carries a large amount of energy. Its visual representation is a light with violet and indigo blue tones, and is responsible for the sky, for example, being blue during the day. Its color temperature is very high, standing at around 3400 and 5000 Kelvin.

This type of light is not only on our screens, it is something of natural origin and that is why it is present everywhere thanks to the rays of the sun. During the day, the sun bathes certain regions of the Earth, electromagnetic waves collide with gases in the atmosphere and this is how the blue color of the sky is generated, and it is also for this reason that we do not see the stars by day.

Blue light also has positive effects for human beings, since it is in charge of regulating the sleep cycles of living beings. It is responsible for suppressing the synthesis of melatonin, the sleep hormone, and that is why, normally, we sleep at night and are active during the day. Of course this is referring to natural light, but what about artificial light?

Artificial blue light and its effects

In addition to the sun, artificial light is also found in electronic devices with lampshades and LED lamps that are so fashionable today for performance and consumption. These devices generate large amounts of blue light to which we are continuously exposed while looking at the screens of our mobile phones or PCs.

The bad

As we say, this light suppresses sleep hormones, having harmful effects if we are exposed to large amounts, as they will cause insomnia. But to this we must add the effect of the blinking of the screens, which is caused by the LED backlight that is responsible for generating the light in them.

An example in which we will notice the flickering is in the slow motion shots of the television, if they focus LED lights we will see that they flicker and it is of course due to the frequency at which it works on electric power (50 Hz). Well this is also harmful, since it will cause us to lose sharpness and clarity in the image. Many screens currently have anti-flicker technology to suppress these effects, thus improving the image quality and the feeling of sharpness so that our eyesight becomes less tired.

Other detrimental effects are dry eyes, having them open longer in front of a screen and, therefore, headaches, which can lead to migraines over time. Eyestrain is another common symptom and loss of sleep if we are at night in front of a screen.

The good

But not everything is negative in blue light, in addition to regulating our sleep cycle, it helps to raise body temperature and improve memory when we study. To a greater extent with natural light, not in front of a screen, although there are many people who study at night, personally I have never done it and never will, I am incapable.

The fact is that blue light in classrooms and offices has also been shown to help improve student performance, however, as long as this exhibition does not continue until late at night.

Also when we drive and are sleepy they have a positive effect, since it will eliminate the feeling of drowsiness in the same way that we drink coffee. But hey, we can see that they are effects that have little to do with the ones that interest us, the screens and computer monitors.

What is a blue light filter

Now that we know the implications that blue light has on us and that screens generate it in large quantities, we must know that practically all screens have a blue light filtering system. But we can also use programs or applications that will allow us to filter blue light.

Screen filters

Normally it is the screens themselves that passively implement these filters in the panel design itself, so a large amount of blue light is already filtered without the need for us to do anything ourselves.

But, in addition, through an option in its OSD panel we can have another filter that will allow us to choose the level of blue light that we want to eliminate. This is basically done by removing white light from the panel by obstructing it using orange tones that take pixels from the screen.

Filters in operating systems and applications

Even operating systems like Windows 10 have a blue light filter to use when we want. In his case, this filter is called " night light " and is a good example of how by using light filtering, the screen turns more orange and the colors paler. In this way, the brightness will not be as powerful and our eyes will rest more, although of course, those orange tones worsen image fidelity.

As indicated, these filters are recommended for night hours and in dark rooms, this way the contrast will be less and the typical white image will not affect us as much.

Filters on mobile screens

In the same way, we also have applications for our mobile that will allow us to configure a "night mode" to further filter the blue light that these screens generate. They work exactly the same as PC applications.

Conclusion on blue light and use

As we have seen, blue light is quite harmful in high amounts for humans, and that is why especially those who work long hours in front of a screen should use one of these filters that we have discussed.

We really notice the difference between using it and not, and it never hurts to watch over our eyes. We hope that this information has been useful to you and that you know better what blue light consists of and how to avoid it.

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If you have questions about the subject or know more effects or characteristics of blue light, write us in the comments, it is always good to learn more.