What is blue light, and how does it affect us?

What is blue light, and how does it affect us?

For most of us, a busy and tedious day ends with a normal routine of relaxing. We roll up in bed with the lights off, with the phones in our hands. Hours before sleep are often spent watching an endless pile of viral memes and cat videos. For others, reading articles on scientific blogs is obviously the way to success.

But do you know that using a phone, a tablet, or a laptop in the dark is not a very good idea? All electronic devices with screens emit blue light that has proved to be very harmful to our eyes. It can physically damage our eyes as well as disrupt our sleep cycle.

What is blue light?

Blue light is everywhere because it is produced by both artificial light sources and our greatest light source — the Sun!

All we see is that light beams are reflected from the surface of objects and processed by our eyes. Human eyes are able to process . The smaller the nanometers, the shorter the wave length.

This visible spectrum of light can be divided according to wave length into three categories: short . The blue light begins at 380 nm and ends at 500 nm.

Light with shorter wave lengths has a greater penetration power. In 1900, Planck found a connection between photon frequency and its energy. Light with shorter wave lengths has higher frequencies, and the higher the frequency of light, the stronger its energy.

The strong energy of the blue light allows it to pass easily through the cornea and the crystal of our eyes. The blue light has the shortest wave length in the visible spectrum, so it has the greatest energy and is the long-lasting effect. It slows down the retina of the eye.

The limited effect of blue light is not so bad. In the end, blue light is part of sunlight. In fact, it is important to regulate our sleep cycles. One way to overcome the change in time zones is to spend time under direct sunlight. Why? Because blue light drops our internal clocks. For the same reason, we are usually vigilant and active during the day, but we feel sleepy and tired at night.

Blue light and its effect on our health

The circade rhythms are the internal biological clocks that all living organisms possess, which coordinate the physiological and behavioural activity of living organisms within 24 hours, and the circadal rhythm depends on the intensity of the light and the temperature of the environment.

There are two major hormones that regulate our zircad rhythm: melatonin and serotonin, the first one also called sleep hormone, and the second one called the chemical substance of the brain "happy" or "good well-being."

The secretion of melatonin is triggered by the absence of light, the blue light of the sun regulates our zircad rhythm, suppressing the secretion of melatonin.

On the other hand, serotonin secretion is stimulated by sunlight. Serotonin improves cognitive functions and is responsible for the bright and happy state of mind. As the effect of bright light increases, serotonin increases accordingly.

They found that blue light also plays a role in regulating our mood and determining how we deal with emotional problems, and they show that blue light reinforces and stimulates the connections between different parts of the brain that process language.

The recent problem, however, is the brightness of the screen we look at every night, which is the reason why the harmful effects of blue light are becoming more visible now than ever before; in other words, the problem is not so much the effects of blue light per se, but the extent and timing of its effects.

One study compared the difference between reading a normal book and reading an electronic book before sleeping. They noticed that participants who use an electronic book not only went to sleep longer, but also were less careful in the morning. The likely reason for this is that the effect of the blue light on the light-emitting reader suppresses the production of melatonin while increasing mental activity. This leads to a deterioration in the quality of sleep and, as a result, to a decrease in activity the next morning.

So far we've been discussing the indirect effects of blue light on our body, the visual effects of blue light, however, are much more direct; as mentioned, we humans have adapted to blue light in natural sunlight for thousands of years.

How did we evolve to cope with the blue light? Our eyes' natural lenses contain certain structural proteins, as well as specific enzymes that absorb a high proportion of light of short wave length to protect our eyes.

However, over the years, when our eyes absorb harmful blue light, it leads to a state commonly known as cataract, because these proteins and enzymes absorb light with a short wave length, our lenses become more murky and less transparent.

Not only this, but also the infiltration power of blue light also destroys retina cells. The effects of blue light may even lead to the formation of jet oxygen molecules in the eye cells, which further contributes to cataract formation and the degeneration of the yellow spot.

Blue light filters

So what can we do to reduce the damage caused by blue light? We can't all turn into electronic devices, which means the answer is blue light filters.

As research continued, and technology companies now understand the harmful effects of blue light, they began to turn the filters into devices that reduce the radiation of blue light.

The laptops are now supplied with a night mode option for their screen displays, which makes them much softer for the eyes. Some Samsung phones have built-in blue filters. The use of these modes or filters at night is better for our eyes, as well as for sleep cycles.

Apple, for example, offers the Night Shift application on its devices, which uses the location and time of the device to automatically switch colour tone and filter blue light radiation.

If your phone does not have a built-in blue filter, there are many free and paid applications to filter blue light. These applications work by changing the color tone of the device screen.

In addition, in order to protect the quality of your sleep, avoid electronic screens an hour or two before you go to sleep. Return to reading a simple paper book before sleeping, though it is easier to say than to do. If you need to use devices before sleeping, keep the night lamp on and activate the blue light filter on your electronic device.

We live in an era where it is almost impossible to do without electronic devices, but, like everything else in life, balance is the key!