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Blue Light Filters: Are they Really Effective?

Are there better ways to protect our eyes, minds, and bodies?

With humankind spending more and more time in front of multiple electronic devices such as phones and laptops, our eyes are sure to go for a toss. Especially after the “Who must not be named” lockdowns, our screen times have gone over the roof for different reasons, ranging from extended working hours to kids attending online classes. 

This has also led to many people complaining about their sleep cycles going haywire, dry eyes, and headaches.

There has been lots of chit-chatter about how these devices also emit Blue Light, which affects our health and sleep cycles in recent times. Thus, many mobile companies have started adding Blue Light filters/night Modes on their phones, claiming to help the users sleep peacefully and reduce the device’s effect on our eyes. 

But do they work?

Disclaimer: If we do a quick Google search about the topic, we will find an enormous amount of contrasting arguments on the same. I’m no expert myself and simply started writing about this topic because I was curious and wanted to share my learnings. Please consult your doctor for any medical advice.

What is Blue light?

Visible light is much more complex than you might think. Our everyday activities and exposure to different forms of light (indoor and outdoor) have different effects on our bodies.

The blue light is a color on one end of the visible light spectrum (consider sunlight’s VIBGYOR) that human eyes can see. It has a shorter wavelength, which produces higher amounts of energy and is similar to ultraviolet rays. So they’re also called blue-violet or violet light. 

This is why the invisible electromagnetic rays just beyond the visible light spectrum are called ultraviolet (UV) radiation.

Blue light is generally defined as visible light ranging from 380 to 500 nm. It is sometimes further broken down into blue-violet light (roughly 380 to 450 nm) and blue-turquoise (approximately 450 to 500 nm). So about one-third of all visible light is considered high-energy visible (HEV) or “blue” light.

How is Blue Light affecting us?

Until the invention of artificial lighting, sunlight used to be the primary source of Blue Light, and we used to get the most of it when we were outdoors during the daytime. Humans did not have much access to it after sunset and spent their evenings in relative darkness.

Now, with most of us basking in light even in the evenings, we have started to take things for granted, thus paying the price. While Blue Light does boost your attention, reaction times, and mood — it seems to be the most disruptive at night.

Studies by the U.S National Library of Medicine (NCBI) have shown that Blue light penetrates the retina and damages light-sensitive cells. Yet, digital devices are essential in daily living for most people, so they disregard their digital health.

The screens of these devices emit short-wave Blue light. This can contribute to various health problems. According to the International Agency for Research on Cancer (IARC), blue and violet light rays can cause cancer, retinal damage, melatonin disruption, AMD, etc. Also, long-term exposure to Blue light can permanently damage your eyes. It can further contribute to blurred vision, sleep loss, fatigue, and dry eyes. These are symptoms of digital eye strain or computer vision syndrome (CVS). In addition, CVS can trigger neck and shoulder strain.

So do Blue Light Filters Work?

A Study by The University of Manchester

Recently, I found a study published by The University of Manchester that established that Blue light filters might trick our brains into thinking it’s daytime, precisely the thing they were designed to avoid.

The filters were designed to reduce a protein in your eye called melanopsin which responds to the intensity of light, especially when that light is of a shorter wavelength, i.e., blue lights. When the screen is tinted yellow, the blue portion of RGB lights is lessened considerably.

The study also found that warm, yellow light tricks your brain into thinking it’s daytime. The warmer colors tell your body clock that it’s sunrise or sunset, in either case telling your body that it’s not quite time to go to sleep yet. 

After reading this article, I did switch on my phone’s Blue light filter to confirm the same, and realized that I had never thought of it that way!

They also suggest that using dim, cooler lights in the evening and bright warmer lights in the day may be more beneficial. Creating a twilight ambiance could be the visual cue your body needs to get into sleep mode.

Apart from the study mentioned above, there have also been loads of user views uploaded claiming that using the blue light filters reduces the clarity of images presented on these devices and is uncomfortable to use. This makes the user switch off the filter for better comfort.

A Study by the University of Houston

On further research, I found another study conducted by a team including Lisa Ostrin, an assistant professor at the University of Houston College of Optometry. According to the same, after two weeks of special eyeglasses to filter Blue light, the participants’ melatonin levels had increased by 58 percent. And they reported better sleep. She also suggests that though special glasses are more effective for blocking Blue light, the filtering apps can still help, though not to that extent.


Unfortunately, though a significant amount of studies have been performed on the effect of Blue light themselves, not much has been performed on whether the filters are effective. The research by the University of Manchester mentioned above is the only one that I found out — it is also the only one that is part of most (since I have not seen all of them) of the articles on the web.

This might be a massive marketing strategy for Mobile/App companies or probably not! Moreover, there have not been significant studies on whether these apps help you sleep better, their prime marketing strategy.

After glasses, the next option is the Screen filters, which work like computer glasses. They’re coated with a material that reduces the blue light that gets through. They are made of an anti-glare filter. Anti-glare materials are consist of acrylic or polycarbonate plastic. Such materials are natural UV filters.

Multiple apps claiming to be good Blue light filters are available for free on the web. However, they are not as effective as screen filters. Further, color distortion and contrast reduction can be inconvenient for some people. It is difficult for the human eyes to focus when the true color is distorted.


So should you use them? Or not?

Below are some options:

  1. Since we do not know whether they work, the best option would be to use spectacles/contacts with the Blue light filters. This is because they are supposed to be the best in this scenario.
  2. The next option would be to use direct Screen filters instead of installing apps.
  3. The apps should probably be the last option, especially if you are one of the increasing numbers of the population suffering from insomnia or any other sleep disorders.

The best option at the end of the day would be to dim all lights and create the required environment for your sleep, about one or two hours before going to sleep. But unfortunately, electronic devices and increased screen time have become an irreplaceable part of our lives. Therefore, it becomes vital to take care of ourselves and the next generation in such a situation.

Recommend0 Simily SnapsPublished in Non-Fiction, Opinion Piece, Self-Help