The Ultimate Guide to Blue Light Filters

From Iris, f.lux, Redshift and other blue light filter desktop softwares for blue light reduction to Android screen filters, blue blockers, transparent sheets and everything in between this is the biggest collection of tools to remove the blue light from your life but first, let one thing be clear:

You are not going to die

Blue light is just blue light. Yes, it’s the most high-energy wavelength of the visible light but we have it everywhere around us.

Even if you place blue LED in front of your eye you are not going to be blind in a couple of seconds but still, prolong exposure to blue light may cause permanent damage in the long run.

I’m not going to go into details why you would want to block blue light from your life.

If you are on this page you probably know a thing or two about the negative effects of blue light on our sleep and eye health.

With our constant exposure to digital screens, we should be at least slightly aware about our blue light exposure and how much time we spend in front of computers daily.

Taking this into account let’s look at all known ways to block light around us from entering our eyes.

How to block blue light?

You have 6 ways to block blue light from your life and screens.


The first one is to place something on your eyes. This is what blue light filter glasses, orange glasses, and just regular sunglasses are.

Plastic Sheets

The second is to place something on your screen. In the most basic case, it can be just some orange, red or yellow sheet but some companies make a little better filter sheets and they cut it in the right size for you plus some glue to look more beautiful.

Native Filter

The third is to use special software which can lower the blue light programmatically with the help of the video card. This is what Iris, f.lux, Redshift and every native blue light filter application does.

It’s super effective, cheap and customizable solution, but also has some drawback like it can’t block just blue-turquoise blue light or part of the spectrum of blue light. Effects like this can only be achieved with glasses or physical filters.

Some monitors also have something called Low Blue Light mode but most of the time it’s just a marketing trick for something that every monitor has from more than 10 years.

I will talk about this after a moment so let’s return to our ways to block blue light from your life and screen.

Screen Overlay

The fourth way is to place transparent overlay with software on your screen. This is what most Android apps for blue light reduction do.

You may notice how they are redder always and how they are a little worse than software alternatives for your PC but the truth is that there is just no other way for developers to make something better for Android.

On Android devices which are rooted, you can access the device drivers and this is what f.lux and CF.lumen does but most normal people will never jailbreak their phone.

Fortunately in the newest devices, Android includes something called Night Light which is native video card filter and it works at least but bad. No automation, no super low values and the things I really need in one blue light filter like Iris for computers have.

All developers of blue light filter apps would be really happy if Android and iOS open their API to the public but it’s understandable from their side.

If you do something bad with the video card you can make the entire screen of the person black and unusable and eye protection apps are tricky for development.

Aside from this, you can make the screen black the same way with the Screen Overlay on Android but it’s high-level API and I’m happy that it’s open to the public.

Display Buttons

I’m going to put the last two ways into this category because they are basically the same.

Some new monitors come with the so-called Low Blue Light mode this is just a marketing trick for the old Color Temperature menu that every monitor and TV has.

So you can lower the blue light via hardware way on near all monitors but what this is missing is the automation.

This is important because every change via monitor buttons take around half a minute for someone who is fast. Well, you can get this to 10 seconds if you are really fast, but it’s still cumbersome.

I will also mention how you can lower the blue light on every TV later in this article.

Which is the best?

As always there is no best way that some ways which are better for certain situation.

Glasses are great for blocking all blue light around you without touching anything. You can block blue light from your lighting, from the TV and even from the Sun.

Plastic sheets are set and forget and sometimes they don’t make the monitor to look orange, but blue light may not be blocked entirely.

Both Glasses and Plastic sheets are not customizable in their reduction so if you want stronger or lighter filter you need to buy new lenses or sheets.

Native filters are probably the best solution for PC but they do require Root or Jailbreak on your phone. They also can’t work on every device.

Windows Phone and TVs are examples on which blue light filter apps can’t be made.

Screen Overlay apps are great for Android but they decrease the contrast and are not the best solution for eye strain.

Display buttons are better are reducing blue light than any other software but you can’t automate the buttons with software. One thing I work on right now is to combine the automation of Iris with the hardware reduce of blue light via software. Basically to automatically click the buttons via software.

Aside from this, you can’t remove all blue light with Display buttons since they usually go no lower than 4000 K of color temperature which is still a really high amount of blue light.

Low Blue Light screens improve the condition a bit with stronger filters but they too can’t be automated based on the time of the day which is what most software products do.

In conclusion, each of the above methods has some pros and cons that we will discuss in greater details later.

History of Blue Light Filters


Before the beginning of this century, scientist knew that the eye contains 2 types of photoreceptor cells called Rods and Cones.


Out of all photoreceptors in our eye more than 95% are rods.

They are responsible for our night vision and are also really bad at recognizing colors.

Rods are not so sensitive to colors and this is the reason why it’s hard for us to see the color of things when it’s dark.


Cones are mostly around the center of our retina.

Thanks to cones we can see things in bright light be it sun or artificial lights.

There are 3 types of cones: red, green and blue and thanks to them our eye is awesome and detecting colors and distinguishing things with different colors.


Then in 1998 Ignacio Provencio found new photoreceptor called Melanopsin and for the first time proved that light is not only useful for our vision, but it’s critical for many biological processes.

It turns out that Melanopsin is present in much more mammals and it doesn’t play any role in our vision.

The main role of Melanopsin is to control our biological clock and circadian rhythms.

It does this by detecting when blue light is present in our environment.

Melanopsin activates when blue light enters our eye and it sends a signal to our brain that it’s day and our brains stops the secretion of our sleep hormone melatonin.

Melatonin from his side controls a large number of processes in our bodies and is responsible for our good night sleep.

When we have melatonin in our bodies we feel sleepy and this is the reason why you can’t fall asleep when you sit in front of the computer at night.


While Michael Herf didn’t know about Ignacio Provencio at the beginning he created f.lux to match his monitor colors to the light in the room.

The first version of f.lux was something like a command line app which gives you color filters when you request them.

After Michael and Lorna found that the orange screen filter makes them feel more relaxed at night they started researching the topic of light and sleep.

Lorna remembered from a biology class that birds migrated according to the season and the main reason for it was the blue light.

The first version of f.lux automatically synchronized itself with sunrise and sunset and actually, this is the main feature of f.lux even to this day.

Created in 2008 f.lux was the first blue light filter. A lot of other programs came into the following years, blue blocker glasses started to emerge and in one point monitor manufactures started to make low blue light monitors.

Several companies like Microsoft, Google, and Apple integrated low blue light filters into their operating systems and opened the blue light research to the mass audience recently.

We may say that f.lux is the father of all blue light filters but during the years better alternatives started to emerge.

Part of the reason is that the app remains free even to this day and free software generally don’t pay salaries to people who can create great products.


As everything in life, it wouldn’t be a complete story without an open source software.

Inspired by f.lux, Jon Lund Steffensen created Redshift in 2009.

The point of Redshift was simple. Bring f.lux to the Linux world.

Adjusting the screen color temperature based on the time of the day again Redshift was the first open source project for blue light reduction.

Free, open source and customizable the software gained popularity among Linux users.

Over the years the software became more user-friendly, it now has some simple UI and supports several different platforms like Windows, macOS, and Linux.


F.lux and Redshift created the first blue light filter software for the PC but there were 1 billion devices running Android without any solution for lowering blue light.

You may have heard about Urbandroid Team but you probably don’t know about the mastermind behind it Petr Nalevka.

Several years after creating one of the most popular Android apps Sleep as Android somewhere in 2013 he came out with Twilight.

The first blue light filter app on Android Twilight found a way to lower the blue light on the closed Android platform.

While the approach of Twilight is really poor compared to the native gamma approach which computer softwares use, Twilight still made a huge step for improving the sleep and eye health of Android users.

The Color temperature values are not actually real because Twilight is using the Overlay approach with transparent red color but still it was the first solution for Android.


Back at 2015 nobody looked seriously into the eye problems caused by computer monitors.

There were the blue light filter tools like f.lux, Redshift and Twilight but most of the people who knew about them were mostly geeks.

On the other part of the spectrum, there were programs like WorkRave which reminded you to take breaks from time to time but they were just nice to have reminders.

I remember how I searched for weeks programs to help me with my eye pain.

My story was simple. I started working as a programmer at the age of 17 and wanted to become the best programmer in the company.

This goal of mine caused me to spend 14 to 16 hours per day in front of the monitor looking at digital letters and learning new things.

I was going to work for 8 to 10 hours then back home working on a side project which I really wanted to become my own business one day.

After a year of this “balanced” work routine and thousands of artificial tear bottles, I finally decided that maybe I need to go to the eye doctor to see why my eyes were hurting so much.

She prescribed me glasses and for the first time in my life, I felt hopeless about my eye conditions.

This was the turning point after which I started to read everything related to eye pain and eye health.

I started to do some exercises from time to time. I found WorkRave, EyeLeo and other break reminders.

I found f.lux and after some months of experimentation with blue light, rests, exercises and a lot of blinking I actually started to feel really good.

My problem with WorkRave and EyeLeo was that I always skipped the rests on the screen. Even on strict mode, Alt+F4 was closing the rest screen

As I test this again now several years later I see that the program has been improved a lot but you can skip the rest again if you want with some key combinations.

What I wanted at the beginning of 2015 was a break reminding timer which I can’t skip with my programming knowledge.

The first version of Iris was actually just that. I made myself a timer which locks my screen and disables my keyboard on a specific time interval.

I started using my own custom app for break reminding but was still using f.lux for the blue light.

My problem with f.lux back then was that it wasn’t able to go lower than 2700K back then.

It was able during the night to go to 1200K via a special menu but the lowest value during the day was 2700K.

I guess this was intentional but I just wanted to be able to manually customize it. Also, there was no way for manual control, only the day and night things based on the time of the day.

I remember how I wrote to the support e-mail several times and even tried to tweet and write to Herf several times to add manual control.

I never received a response.

After I realized that maybe f.lux will never get an update and my problem will never be fixed I started searching for alternatives.

I’m actually pretty sure that if it wasn’t for Iris f.lux indeed would never receive an update like the resent new version.

Back in 2015, there were no alternatives. A good version of Redshift was just not available and SunsetScreen was still not created.

So I decided to find a way to make this and add a blue light control to Iris.

After several months the first version of Iris was born and it was super ugly.

I didn’t know how to count versions so I just named this Iris-0.0.0. At least it was working the way I wanted a blue light filter to work.

From then on I started improving the program.

I found that eye strain is not only about blue light. There are also PWM flicker, font rendering, blinking, brightness automation, subpixel flicker and much more.

Over the next several years I gradually solved all problems I found.

Iris was free back then and I mean totally free.

After several months of non-stop work, I decided to place a donation button on the website.

I also quit my job to dedicate my life to help people feel less eye strain.

Back in 2015, I believed that people will send me some money because they appreciate my work and I would be able to sustain myself while working full time on Iris.

At the end of 2015 after I almost starved myself to death I realized that I may be wrong.

This was how Iris was looking back then. I actually still have all versions and you can still use these versions of Iris for free but I almost quit.

After 1 year of non-stop work trying to make the best software for eye protection and 0$ revenue from donations, I had 2 choices.

Abandon the project and start a job again or make it work.

As you can guess I choose to give my everything to Iris. I started selling all kinds of Chinese stuff to make some money and made Iris paid.

The software was still too bad for anyone to buy it but after several months I made my first sale, then the second then the third.

Many people these days ask me how I can charge for this kind of software but Iris actually drove the blue light filter revolution.

I chose to make a paid product because I didn’t want to show ads. And I chose to make a great product for few users instead of crappy product for everyone.

Iris was the first product to automatically pause itself when some program is running.

Iris was the first product to have flicker free brightness automation.

Iris was the first product to have a color inversion and black theme on everything

Iris became the first product to support USB monitors even before they made drivers for them.

The first product with UI for Windows, macOS, and Linux.

The first product with native Chrome extension.

First product for iOS without jailbreak.

The first product to work per monitor and first to improve font rendering.

I can talk a lot but Iris inspired the renaissance of blue light filters.

Most of the features in the new f.lux are based on the things that were available for years in Iris.

This makes me happy and I am glad that competition made monitors more healthy for the eyes.

Which brings me to the biggest win for blue light filters which was

Native Solutions

Starting with Night Shift which was actually a really unfair move from Apple to f.lux, Native blue light filter solutions started to emerge.

The unfair thing is that f.lux for years was available for jailbroken devices via Cydia but because it’s using a private API it was against Apple rules and Apple didn’t allow it into the AppStore.

Tasks like this are really good to be handled by the operating system but most of the time their solution to the blue light problem is really bad.

So Apple came out with this groundbreaking innovation called blue light filter and removed the f.lux app from everywhere.

There was some kind of petitions about this but Apple was actually right.

Apps are eligible for Sideloading if they are open source so if the team behind f.lux really wanted to have their application available they could just open the source code.

Since the app was free I don’t see a problem but only they know what works best for them.

The good thing about the whole thing was that companies started to care about blue light all at once.

Microsoft added something called Night Light in the newest versions of Windows 10.

Android also introduced their implementation of a blue light filter also called Night Light.

The good thing about the native Android Night Light is that in comparison to Twilight it’s not a transparent filter but real gamma blue light reduction which works better and increases contrast.

And of course, Night Shift came to macOS.

Every day more and more people learn about the benefits of setting a proper light environment for their eye health.

Every day more and more people learn how to set up and customize their monitor and light for the best eye health and every day more and more eyes are saved from macular degeneration thanks to all these products and much more.

History of Blue Light Filter Glasses

I talked a lot about the software blue light filters but there was one parallel blue light revolution in the face of blue light filter glasses.

I’m not an expert in the glasses side but I think it’s proper to start with

Gunnar Optiks

Founded in 2006 way before f.lux came into existence Gunnar was actually the first product to try to fight computer vision syndrome and to filter blue light with the help of special lenses.

We can say that eye safety glasses were the first blue blockers but still Gunnar Optiks was the first commercial product of it’s kind.

The woman in the picture above is actually Gunnar co-founder Jenny Michelsen.

She started Gunnar in her garage in search of a solution for her husband’s digitally induced migraines.

Jenny son name is actually Gunnar and the name of the company comes from his name.

Here is the full story:

The idea for the glasses was born out of one woman’s frustration with her husband’s digitally induced migraines and worry about the eyes of her child who was fascinated by technology.

Jenny Michelsen’s husband, Matt, was suffering from the headaches he had after hours sitting in front of six computer screens.

The headaches, the Michelsens would learn, were a symptom of Computer Vision Syndrome, a collection of minor ailments that build up over time.

As the Rancho Santa Fe woman urged her husband to see a doctor, she wondered whether her 3-year-old son, Gunnar, was getting a jump-start on similar problems.

If she and her husband believed the computers were getting to their eyes – and they didn’t start using electronics until they were in their 20s – what would happen to Gunnar’s generation?

An estimated 125 million Americans suffer from what is now commonly referred to as Digital Eye Fatigue or Computer Vision Syndrome (CVS), according to the American Optometric Association.

Matt and Jenny Michelsen reached out to their close friend, Joe Croft, a former Oakley engineer, about the issues surrounding CVS.

They wanted to learn more about the effects of focusing on a digital image projected on a screen just inches from one’s face for hours at a time and years on end.

The Crofts and the Michelsens began their five-year road to launch by talking to medical experts.

One of those experts was Dr. Jeffrey Anschel, a Carlsbad optometrist who has become an expert in Computer Vision Syndrome and Visual Ergonomics.

He noticed the problem about 17 years ago when employees of a nearby computer company began complaining about dry and tired eyes and difficulty focusing.

They were problems that people generally didn’t experience until they were in their 40s, but these patients were in their early 30s.

It didn’t take him long to make the connection between their work and the required time spent in front of a computer screen.

“You can work, shop, communicate and do just about everything from your computer now, and people just don’t realize how much time they’re spending looking at the screen.

The digital images that computers project are one factor contributing to Computer Vision Syndrome.  The eye focuses on the hard edge of an image, but digital images don’t have a clean edge.

As a result, the focus drifts forward and back, causing eye fatigue.”

Anschel also noted, “that when people spend long periods focusing on something close to their face, eye muscles tend to lock into a singular position, which is tiring and can push the eye down the path to becoming farsighted.

Meanwhile, the eye has to deal with light from conflicting sources, such as sunlight, that are much brighter than the computer screen.

There’s also glare from the light shining into the eyes.  And the angle of view for the computer screen, which is straight ahead, isn’t desirable.

People tend to focus better at objects when looking down, such as reading a book.”

Croft and Michelsen eventually took a prototype to Anschel and explained the important components of the glasses.

They had an amber-tinted lens, which makes images appear clearer.

Yellow makes images sharper by adding contrast and filtering out blue light.

The lens is also shaped to pre-focus the light into the eyes, so the eyes don’t have to do all the work.

There’s also an anti-glare filter that allows light from the computer in but keeps out distracting reflected light from other sources.

The lenses are also designed to be fitted close to the face, creating a “micro-climate” that keeps away the dry air currents.

This helps keep eyes moist by reducing squinting and maintaining a closer-to-normal rate of blinking - a leading cause of dry eyes.

Croft and Michelsen set out to create a product that addresses the issues associated with digital eye-strain.

They completed their first prototype in 2006.  In early 2007, they founded the company and in October of 2008, they launched their first product.

Investors in the company include Peter Thiel (a founder of PayPal and early investor in Facebook), 50 Cent, Carl Zeiss Vision, Monster, Inc., Christopher Burch and Happy Madison Productions.

I think the Gunnar glasses were the first and main innovator of blue light filter glasses so I will not talk much about others.

Note that many big names and hundreds of different brands make blue light filter glasses so Gunnar is not unique in any way.

Almost all blue blocking glasses do the exact same thing and they do it badly.

I will review many different brands but here are some things I want to make clear now.

Sunglasses block more blue light than many blue blockers.

You can find a test how Sunglasses block as much as 40% of the blue light while some blue light filter glasses block less than 10%.

You can also find Orange safety glasses which are under $10 and block more than 90% of the blue light.

If you have ever been to a dentist for whitening they place you red glasses so your eyes don’t get damaged from the UV light used for whitening your teeth.

Well if you are really concerned about the blue light I suggest you to buy a Dental safety protective glasses which are also under $10 and block all blue light.

This and all other fully red glasses block 100% of the blue light.

I will talk more about the different model of blue light filter glasses but you need to know that most slightly yellow glasses don’t do anything.

They don’t help you to sleep better and they don’t stop a lot of blue light. The truth is that software like Iris is way more if you want to use them in front of a computer.

The only reason to buy blue light filter glasses should be if you have bad lighting or watch a TV a lot and software don’t support your screen.

Another reason is if you want to do some biohacking and wear them outside.

How much Blue light software Blue light filters block?

There is not much information on the internet about how to check if your monitor emits blue light so I did a simple Blue light filter Test:

With your blue light filter look at the image above and if all squares look black all blue light is blocked.

GIF test

You can also use this GIF test here

If the image is black and you don’t see any blue all blue light is blocked.

The latest medical researches, however, point the melatonin secretion is also effected by green light so to test if all blue and green light is blocked use this image:

Ideally, if your monitor doesn’t emit blue or blue and green light you shouldn’t see a change in the color.

You should only see black square without any change of the color or hue like this

For more info about the Iris blue light filter test visit How to check if my Monitor emits Blue light?

Here is an example of how Iris blocks all blue and green light

Test with the images

When no blue light is blocked the white color should look like this

When 10% of the blue light is blocked white color should look like this

When 20% of the blue light is blocked white color should look like this

When 30% of the blue light is blocked white color should look like this

When 40% of the blue light is blocked white color should look like this

When 50% of the blue light is blocked white color should look like this

When 60% of the blue light is blocked white color should look like this

When 70% of the blue light is blocked white color should look like this

When 80% of the blue light is blocked white color should look like this

When 90% of the blue light is blocked white color should look like this

When 100% of the blue light is blocked white color should look like this

If your blue light is 100% blocked white color will actually be yellow.

Note that you can’t actually test how much blue light your blue light filter blocks and if you really need to test this you need a colorimeter.

Here is an example of Iris with Groot color scheme which blocks only blue light without affecting the green light:

If you want to test if both green and blue light is blocked you need to use some other test images.

When no blue light is blocked the white color should look like this

When 10% of blue and green light is blocked white color should look like this

When 20% of blue and green light is blocked white color should look like this

When 30% of blue and green light is blocked white color should look like this

When 40% of blue and green light is blocked white color should look like this

When 50% of blue and green light is blocked white color should look like this

When 60% of blue and green light is blocked white color should look like this

When 70% of blue and green light is blocked white color should look like this

When 80% of blue and green light is blocked white color should look like this

When 90% of blue and green light is blocked white color should look like this

When 100% of blue and green light is blocked white color should look like this

You may notice that most blue light filter softwares actually don’t look like this at high values.

This is because there is a legacy to use Color temperature instead of linear reduction dating to the first versions of f.lux.

However, if all blue and green light is removed the result is always red.

Here is an example at Iris set to 0% blue light which actually removes both blue and green light:

RGB test

While the first test was made for easily test if all blue and green light is removed from the screen it was not really good for finding what percentage of blue light is blocked.

The second test is really good for finding what percentage is blocked but you need a really sharp eye to see the difference in the colors.

This RGB test is something in between. You can test if all blue light is blocked and you can also see some percentage.

Look at the image below with your blue light filter

If you don’t see the blue color all blue light is blocked

If you don’t see the green color all green light is blocked

And here how most blue light filter softwares work at 3400K

To remove all blue light you need something bellow 1900K

and going down even move will remove also the green light

These were basically the test you can do to see how effective is you blue light filter.

You can test this way both software and glasses.

The difference is that with software you will not see emission while with glasses the lest will block the light.

Blue Light Filters Market

In this fictional market, my goal is to collect all products on Earth for reducing blue light.

I’m going to the deepest parts of the web in search of the No Blue Light World.


There are really a lot of ways to block blue light via glasses. There are blue blockers with a yellow tint, with orange, with a red tint or the regular sunglasses also block some of the blue light aside from the UV light.

The best blue blockers look something like this:


Blue light Screen Protector


Blue light filter Apps




I didn’t place a picture of me but if you are really interested how I look like you can see me here.

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