What is a Blue Light Filter?

It's a way to block the blue light directly at the screen!

Unlike blue light glasses that are placed right in front of the eyes to protect them, the filters act directly at the source of this blue light.

But how do they work?
And what are the different types of filters?

We’re giving you here all the details so that you know exactly what is a blue light filter!

what is a blue light filter

A reminder of what blue light is

Blue light is a part of the light emitted by the sun and by all the light sources around us (screens, bulbs, etc.).

If we’re more and more concerned about blue light, it’s because it’s the most energetic light, the one that our eyes has the hardest time filtering and the one that can have negative consequences in the short and long term.

Blue light isn’t necessarily bad:

✅ It regulates our circadian rhythm.
✅ It boosts alertness
✅ It helps memory.
✅ It elevates mood.

But because of overexposure (especially with the screens), many disorders can appear:

❌ Visual fatigue
❌ Dry eyes
❌ Headaches
❌ Sleep disturbances

That's why devices were invented to block part of this blue light. And blue light filters are one of them!

what is blue light

The blue light filter as protective film

First of all, when we talk about blue light filters, it can be a concrete filter that we can touch with our fingers. A filter we have to place ourselves on the screen of our computer or smartphone.

This filter looks like the protective films we put on the screens of our devices!

These two films are very similar. Indeed, they both:

👉 Prevent scratches on the screens.
👉 Protects the screens in case of accidental fall.

However, the blue light filter goes further, because at the same time:

It blocks some of the blue light emitted by the screens.

In the way they work, they’re actually quite similar to blue light glasses: they prevent some of the blue light from reaching the eyes to reduce visual fatigue and the occurrence of headaches at the end of the day.

blue light filtering glasses

Pros & cons of these blue light filters

This type of blue light filter is rather efficient, it has many benefits, but it also has some drawbacks. Here are some of them:

✅ It’s available for all screen sizes, from computers to smartphones.
✅ This filter is not tinted and so it doesn’t alter the perceived colors.
✅ The protection against blue light it offers is sufficient for daytime use.

It blocks less than 50% of blue light, which is not enough for the night.
 Like protective films, it must be perfectly placed on the screen for it to be effective and not be inconvenient
(bubbles, reflections, etc.).

what is a blue light filter film

The blue light filter as an app

But when we talk about blue light filters, we can also mean digital filters. Like the previous ones, these filters can’t be manipulated: they’re available on our computers and smartphones.

This filter takes the form of an app to download directly to our devices!

However, downloading isn’t always mandatory because more and more devices already have this blocking blue light app. Depending on the operating system, the name is always different, but it’s generally referred to as "night mode".

When this application is activated:

👉 The colors of the screen become warmer, with yellow and orange hues.

As with blue light gaming glasses, this is not a color that was chosen randomly:

It reduces the amount of blue light emitted by the screens.

With this type of filter, the eyes receive much less blue light, and it’s useful, especially at the end of the day, to prevent sleep disturbances, including difficulty falling asleep, restless nights and insomnia.

what is blue light filter app

Pros & cons of these blue light filters

The blue light filter that can be downloaded to computers, tablets and smartphones is as useful as it is effective, but it does have a few drawbacks too. Here they are:

✅ It blocks blue light almost entirely.
✅ Since it’s a software, it can be programmed and customized
(activation at specific times, screen tint, etc.).
✅ It’s easy to use and can be activated and deactivated at will.

❌ They change all the colors of the screen, which is annoying during the day but also when watching a movie or TV show.
❌ If it’s not programmed to be activated automatically, we usually forget to turn it on!

what is a blue light filter app

Conclusion: What is a blue light filter?

👍 A blue light filter is a way to block blue light directly at its source, on the screen.

Even if the 2 types of filters have cons, they can however be complementary:

✅ The film filter provides daytime protection (while at the same time protecting the screen from scratches and cracks).
✅ The blue light filter app allows better protection at night, provided it’s programmed to be activated automatically!

The blue light filter is therefore an ideal solution to discreetly and effectively protect our health from overexposure to screens!