Greetings again my dear friends of this prestigious platform, especially to the members of the @project-hope community, it is no secret that our body represents a physical entity of great complexity, where countless phenomena are developed in order to function, therefore, we find as main phenomenon the movement, and from there others are generated such as sound, and of course, the light.

The phenomenon of light has allowed us to visualize our wonderful environment in the most accurate way possible, in general we can say that every object or body around us becomes an emitting agent of light rays and these rays are included in every fraction or part of such objects or bodies, and this can be checked by changing our viewing position.

Therefore, without light it would not be possible to observe everything that surrounds us, and this aspect can clearly be verified both in the field of science and technology, with the passage of time man has had the enormous capacity to design wonderful instruments or electronic devices that today have an essential influence on our lifestyle and among them we find devices such as cell phones, tablets, computers, televisions, where the use of light is essential for its proper functioning.

In previous articles we have been related to some of these instruments or optical devices such as the compound microscope, sextant, telescopes, binoculars, among others, some project light rays directly to our natural receiving screen such as the retina, and others do it to a certain artificial screen and from there to our eyes.

This time we will focus on those devices that treat light internally and then take them to their screens and from there to our eyes, these devices are mainly the cell phone, tablet, computer and televisions, and we know that these devices are of great use in our lives, however, the long period of exposure of our eyes to these devices has aroused the interest of both the world of science and the area of technology.

To deepen the purpose of this article we must say that the visible or white light that constitutes our electromagnetic spectral fraction and that our eyes can capture, is constituted by several colors, among them we can find orange, red, yellow, green, indigo, violet and blue, a clear example of these colors is the dispersion observed in a rainbow when at certain environmental conditions and the angle of our position we can witness the composition of all these colors.

Our eyes are able to differentiate each color due to the wavelength of each of these colors, that is, our eyes will perceive each of these colors according to their amount of energy and the same is linked to the wavelength, and thus with its frequency, therefore, the shorter the wavelength the higher the frequency and amount of energy, this makes certain rays shine with less or more intensity than others.

The aforementioned is of great importance for the proposed analysis since our eyes will be exposed to this type of energy represented in these waves that represent each color and the greater the energetic capacity, the greater the risk to our eyes, then, the screens of the aforementioned devices are responsible for bringing the light treated inside these devices to our eyes.

Of the component colors of our white light, the blue sub-fraction represents the greatest risk to our retina because it is the one with the most energy except for violet, however, blue light represents approximately 25% of the entire spectrum of our visible light and thus has a great impact on our visual sense.

The screens of the mentioned current devices, especially those of LED type, project more blue light than any type of natural source, and therefore, by not controlling our prolonged exposure to these devices we can be victims of severe damage to our retina, especially to a tissue very sensitive to light which is called macula, affecting the cells of this and these cells do not have the ability to regenerate, hence the great risk of long-term blindness, also generating other problems such as headaches, stress or visual fatigue, among other adverse effects.

It is important not to expose our vision to long periods of time in front of these types of devices, however, there are some types of lenses that work as a filtering agent of these rays and can protect us from the actions described above, science always hand in hand with technological advances because the generation of constant devices make many people dependent and sometimes we neglect the adverse effect that can generate in our body health, in this case our essential visual sense.

There are also other recommendations such as not to observe for a long time these devices without lighting around us, since this causes the light from these devices to concentrate with greater intensity in our eyes, and with it, the short-wave blue light (blue-violet) which is the one that harms us, since the blue-turquoise sub-fraction of longer wavelength is beneficial to our visual health, then we will see some of these examples in Figure 1 below.

Figure 1. Avoid using devices such as cell phones, computers, televisions or tablets in the dark

For example, if we are exposed for 20 minutes in front of these devices, we should take the time of 20 seconds observing at a distance of 20 feet towards any part, among other preventive measures.

Until another opportunity, my dear readers, hoping to count on your important comments for the consolidation of the issue raised.

Note: Figure 1 is of my authorship and made in Power Point.

Bibliographic References

[1]Las pantallas de celulares, computadoras y televisores pueden llegar a dañar nuestra vista.

[2]UNDERSTANDING BLUE LIGHT.