How to protect your eyes from blue light

Blue light emitted from tablet and smartphone screens suppresses the secretion of melatonin, which is our brain's signal for the start of the day and a signal to increase brain activity. Whether you're browsing the Internet, reading an e-book, or texting friends before bed, launch apps that can help protect your eyes and help you fall asleep faster.

As recommended by experts, we should avoid screens from electronic devices three hours before bed to avoid disrupting the normal cycle of brain activity. Nowadays, however, this is almost impossible, since many people do not part with their phones even in bed.

Luckily, we have a solution! It is enough to download one of the presented applications, which includes a special color filter on the screen in the morning and evening to change the color of the emitted light.

In the Google Play store you will find many applications with such properties. We have chosen for you Five of the best and free blue light blocking apps to help you fall asleep.

Each of them performs a basic task, but, in our opinion, Twilight deserves the most attention. The app is stable, offers the most useful features in the free version and has no ads.

Twilight application - for night surfing the Internet

Twilight is an application that has been accompanying me on smartphones for several years now, and I can’t imagine surfing the Internet at night without it. This is definitely the most pleasant application of all presented.

Firstly, it is available in Russian, and secondly, it is not confusing with an excess of settings. Here you will find only the functions that are most important: color temperature, intensity and screen dimming.

Twilight also allows you to set when filtering will turn on based on certain parameters. For example, we can program the application to turn on the filter immediately after sunset, depending on our chosen time zone and system settings.

The application is always active in the notification panel, so you can turn it on at any time of the day with one click. If you have Philips Hue lighting in your home, you can integrate Twilight with it. Then, at the selected time, the smart light bulbs will change their color to warm.

The Twilight app lets you save multiple profiles, so you can quickly switch between frequently used settings.

CF.lumen – great personalization options

We can recommend CF.lumen to people who are looking for greater personalization options. First of all, the program offers a choice of different color filters depending on the time of day. In addition to the most commonly used red light, you can also find filters in green, yellow or pink.

An interesting addition is the ability to enable the function activation of the filter under the influence of darkness (Sleep in the dark – if the application recognizes using the exposure sensor that we are in the dark, it automatically changes the color scheme of the screen).

Unfortunately, the interface is text-based, so users who do not know English will have problems with the controls. Unlike Twilight, we will not find here the ability to disable filter options directly from smartphone notifications.

EasyEyes app – simple and minimalistic

EasyEyes is an application for users who love minimalistic interface and ease of use. After downloading the app, simply click on the eye symbol in the main program window to turn on the blue light filter. That's all philosophy is.

Of course, there are also additional settings here: changing the intensity of the filter or defining the hours at which it should be activated. Since these options are hidden in the sidebar, the application seems very simple.

The only drawback is the advertisements that are fired from time to time when the parameters are changed.

Blue Light Filter – a combination of beauty and stability

The creators of Blue Light Filter tried to ensure that their application not only worked well but also looked beautiful. As with Easy Eyes, once you've downloaded the app, just tap on the moon symbol to activate the filter.

The color of the light can be selected by clicking the corresponding icons (eg candle, sunset, incandescent), while other parameters are controlled using sliders.

The filter operation schedule can only be set “manually” by specifying the start and end time. The shortage of available functions is diversified by a pleasant little thing - a shortcut in the notification panel, with which you can quickly launch and pause the application.

Lux – eliminates blue light without distorting colors

Although the above filters are effective in eliminating blue light, changing the color tone of the screen can be tedious for some people. It is for such users that the Lux application was created, which does not change the temperature of the screen light, but only affects its brightness.

In this way, we do not completely get rid of the negative effect of blue, but we limit its influence.

Lux offers a range of activity-based profiles that are accessible from the notification panel and a variety of detailed brightness settings. In particular, we can reduce the backlight intensity level, decide on the highlighting of buttons, determine the speed of brightness reduction, etc. A useful feature is the ability to use shaking to increase brightness.

If while using the application we find that reducing the brightness does not bring the expected result, then with the help of an additional setting we can enable the night mode, which, like other applications, activates the blue light filter.

A few additional settings are available in the full version of the application (for example, determining the time of sunrise by location), but, in our opinion, it is quite possible to do without them.

Headaches, deterioration of vision and memory, insomnia, depression, obesity, diabetes and even cancer - there is an opinion that one or several of these troubles are overtaking you right now, slowly but inevitably, and the reason is in the blue spectrum of the radiation of your display devices, even a smartphone, even a PC. To protect users, more and more manufacturers are building blue light filters into their software. Let’s figure out whether this is a marketing ploy or whether filters really help, whether gadgets are dangerous for sleep and health, and if so, how to live next.

Blue radiation: what is it and is it harmful to health?

By its nature, light is electromagnetic radiation, the visible range of which is characterized by a wavelength from 380 nm (the border with ultraviolet radiation) to 780 nm (respectively, the border with infrared radiation).

Why is it blue light that causes the greatest concern among scientists and doctors? Let's break it down point by point.

Reduced image clarity. Blue light is characterized by a relatively short wavelength and high vibration frequency. Unlike, for example, green and red, blue waves only partially reach the fundus of the eye, where the receptors are located. The rest dissipates halfway through, making the picture less clear and therefore causing more strain on the eyes. As a result, with an excess of blue color, we get increased eye pressure, fatigue and headaches.

Blue waves only partially reach the bottom of the eyeball

Negative effect on the retina. The energy of photons is inversely proportional to the length of the electromagnetic wave, which means that short-wave violet and blue radiation has more energy than any other. When it enters the receptors, it causes a chemical reaction with the release of metabolic products that cannot be completely utilized by the surface tissue of the retina - the epithelium. Over time, this can seriously damage the retina and cause vision impairment and even blindness.

The international standard for ophthalmic optics ISO-13666 identifies blue light as the most harmful to the eyes.

Sleep disturbance. Evolution has trained the human body well: when it gets dark, you want to sleep; when it dawns, it’s time to wake up. This cycle is called the circadian rhythm, and the hormone melatonin is responsible for its correct operation, the production of which ensures sound and healthy sleep. Bright light, including from the display, disrupts the production of this “sleep hormone”, and even if we feel tired, we cannot fall asleep - there is not enough melatonin. And regular nightly vigils in front of a screen can even lead to chronic insomnia.

By the way, here too the color and intensity of the radiation have an influence. Agree, we sleep much more comfortably in the dim light of a yellow night light than under a bright fluorescent lamp (and it would be better, of course, in complete darkness). For the same reason, it is extremely rare for diode indicators in televisions and other electronics to be blue - they themselves are much brighter than red and green and peripheral vision is much more sensitive to them.

Other hazards. The consequences listed above are now considered proven through decades of independent research in this area. However, scientists continue to study the effects of blue light on the human body and receive disappointing results. It is likely that circadian rhythm disruption significantly increases blood sugar levels and can lead to diabetes. The hormone leptin, which is responsible for the feeling of fullness, on the contrary, decreases, and as a result, a person will experience a feeling of hunger even if the body does not need food.

Thus, regular use of gadgets at night can provoke obesity and diabetes - due to the greater amount of food consumed, coupled with a disrupted sleep cycle. But that's not all. Harvard Medical School suggests that shifting cycles and regular exposure to light at night significantly increases the risk of cardiovascular diseases and even cancer.

Who is affected and is all blue light harmful?

It is well known that with age, the lens of the eye becomes cloudy and, accordingly, transmits less light, including blue light - the visible spectrum slowly shifts over the years from the short-wavelength to the long-wavelength spectrum. The greatest permeability to blue light is in the eyes of a ten-year-old child, who already actively uses gadgets, but does not yet have developed natural filters. For exactly the same reason, regular users of gadgets with increased light sensitivity or with an artificial lens without a blue light filter are most at risk.

There is currently no clear answer as to which blue radiation is harmful and which is not. Some studies claim that the most harmful spectrum is from 415 to 455 nm, while others indicate the danger of waves up to 510 nm. Thus, to reduce the risks associated with blue light, it is best to shield yourself as much as possible from the entire short-wavelength visible spectrum.

How to reduce harm from blue radiation

Pause before bed. Doctors recommend refraining from using any devices with a screen at least two hours before bedtime: smartphones, tablets, TVs, and so on. This time is just enough for the body to produce a sufficient amount of melatonin, and you can fall asleep peacefully. The ideal option is to go for a walk, but for children, spending several hours in the fresh air every day is absolutely necessary.

Blue blockers. In the 1980s and 1990s, during the heyday of personal computers, the main problem with monitors was radiation from cathode ray tubes. But even then, scientists studied the features of the influence of blue light on the human body. As a result, a market has emerged for so-called blue blockers—lenses or glasses that filter blue light.

The most affordable option is glasses with yellow or orange lenses, which can be bought for a couple of hundred rubles. But if you wish, you can choose more expensive blockers, which, with greater efficiency (filtering up to 100% of ultraviolet radiation and up to 98% of harmful short waves), will not distort other colors.

Software. Recently, OS and firmware developers have begun to integrate software blue light limiters from displays into some of them. They are called differently on different devices: Night Shift in iOS (and macOS computers), Night Mode in Cyanogen OS, Blue Light Filter in Samsung devices, Eye Care Mode in EMUI, Reading Mode in MIUI and so on.

These modes will not be a panacea, especially for those who like to spend the night watching social networks, but they can still reduce the harmful effects on the eyes. If this option is not available on your device, we recommend installing the appropriate application: f.lux for rooted Android devices, or Night Filter for non-rooted gadgets. The same f.lux can be downloaded and installed on computers and laptops with Windows - it has a number of presets, as well as the ability to customize the schedule at your discretion.

conclusions

Night vigils in front of a smartphone or TV screen do not fit into a healthy lifestyle at all, but it is the blue spectrum radiation that significantly aggravates the situation. Its effects definitely lead to fatigue and blurred vision. In addition, it disrupts the sleep cycle and, possibly, leads to obesity and diabetes. The possibility of increased risk of cardiovascular disease and cancer due to exposure to light requires further study. Thus, there is every reason to refuse to use any gadgets a few hours before bed, or at least turn on the software filters that most developers today preinstall in their software. It definitely won't get any worse.

To what extent can this or that type of lighting affect our health and vision? Is it true that blue light is harmful to the eyes?

Let's look at what you really should be wary of and what rules you should follow when organizing lighting in your home.

At different times of the day a person needs lighting of different brightness. Each of us has a so-called internal clock or circadian system.

She must receive the right signals. Based on the ambient light, the body determines what time of day is currently around it - morning, afternoon, evening, night, and how it should behave.

All this regulates the hormonal system and is responsible for sleep and wakefulness. The amount of light we need depends on:

1. tasks that you are going to solve

1. time of day

1. your age and many other factors

How to maintain health and make good use of artificial lighting at home and at work? To do this, follow five basic rules.

1 1 hour before bedtime, do not turn on cold light sources.

During the day they are certainly useful, especially in confined spaces in workplaces where increased concentration is required.

But not in the evening before going to bed. By the way, in addition to LED and fluorescent lamps, such harmful sources include televisions, computer monitors, and smartphones.

Also turn off bright overhead lights in advance.

2 When sleeping, completely turn off all light sources nearby.

Forget once and for all about night lights that burn all night long. They will bring nothing but harm to you and your children. Especially those emitting blue and violet light.

If you really need a night light, then choose models that are predominantly red.

Also, when you are in bed, there should be no light in your direction:

1. backlit clocks, computer systems

1. charging indicators

1. anti-mosquito lamps

1. aquarium lighting

Weak bedside lights will quickly send you back to sleep. But overhead light stimulates the production of serotonin well and suppresses the formation of melatonin, which makes you sleepy.

4 During working hours, always try to be in a brightly lit room.

Lack of light in the workplace and non-compliance with lighting standards always affects performance, fatigue and vision.

Now about the blue light. There are a lot of myths and misconceptions about him. Some in their theories go so far as to consider any LED lighting containing the blue spectrum dangerous.

The number of contradictory materials, articles in magazines and the Internet on this matter makes us at least wary, but still does not bring complete clarity.

So which of these is true and which are lies and myths?

In order to dot the i’s once and for all, the international commission on illumination CIE (International Commission on Illumination) on April 23, 2019 published an official statement regarding the “harm” of the blue spectrum.

Here are the main points that were voiced in the statement:

1 The term “blue light hazard” itself should ONLY be used when considering the risks of photochemical retinal damage from very bright sources.

For example, the sun or electric welding.

2 The duration of exposure to such rays must be very long for them to actually pose a potential threat to vision.

That is, not only LED, but also fluorescent and even ordinary bright incandescent lamps can be dangerous.

4 Permissible blue light exposure levels can never be exceeded by any reasonable use of luminaires.

Moreover, simple long-term contemplation of the blue sky is sometimes even more dangerous than the radiation from most LED lamps.

That is, roughly speaking, don’t shine a light bulb in your face, and everything will be fine.

Hypothetically, a white light source emitting blue light at levels close to dangerous would be extremely bright. Such a lamp would cause you obvious discomfort, and you would have no desire to sit under it.

Moreover, keep looking at him.

What light sources should you still avoid? You should be wary of lamps that produce intense, bright blue or violet light.

First of all, they pose a danger to children. The same exposure to such light sources on the eyes of a child and the eyes of an adult leads to different consequences.

Therefore, parents are not recommended to buy toys for their children that contain bright blue LEDs. Especially if they are very close to the violet component of the spectrum.

You can download the statement of the international commission (in Russian) regarding the dangers of blue light from the link - here.

But if you still often have to work with unsafe blue light sources, how to protect your vision in this case?

As mentioned above, try to avoid them as much as possible at least an hour before bedtime.

For safe computer work, special blue blockers appeared back in the 90s. These are lenses or glasses that blocked and did not transmit blue radiation from monitors.

Expensive glasses options completely block ultraviolet waves, and more than 98% of harmful short ones.

The most affordable options cost a few hundred rubles and have yellow or orange lenses. However, they distort the overall color image you see through them.

In recent years, almost all manufacturers have begun to build in software the ability to limit harmful blue and ultraviolet radiation from their gadgets, smartphones and TVs.

Look for such a function in the settings, you will definitely find it. If your device does not have this, you can install special programs. They are freely available. For example f.lux