Who else starts their day by checking the phone? Then, how many hours do we work in front of a computer? Once home, we relax while watching TV or some TV series on the tablet. And later, exactly before falling asleep, we take a last look at our mobile phones. Screens are everywhere and attached to us practically the entire day.
This is a routine that is very common among millions of people around the world. So, what is wrong with it? Well, scientists and doctors have long warned that the constant repetition of this prolonged screen time could explain some annoying symptoms, such as eyestrain, blurry vision, headaches, dry or irritated eyes, neck and back pain, and even insomnia. And there is more! Debates about the potential damage that blue light can cause to our general health are becoming more and more intense. Sleep scientists, eye doctors, and tech companies are all getting involved. Blue light is spoken of as a real risk for adults of all ages and children.
So, is the blue light too bad? Is it an avoidable risk? Can computer glasses fix that? Let’s find out!
What is blue light? The science behind it!
Light, in scientific terms, is made up of electromagnetic waves. These waves vary in length and energy. The visible spectrum, the tiny part of this range that our human eyes can actually see, includes all the colors of the rainbow: red, orange, yellow, green, blue, indigo, and violet.
Blue light refers to a specific range of wavelengths, typically between 415 and 495 nanometers. It is high-energy and short-wavelength, which means it vibrates faster and carries more energy than most other visible colors. That high energy is exactly what gives blue light its unique (and controversial) properties.
The fact is, blue light is everywhere in nature. The sun is its biggest source. Actually, the reason the sky looks blue during the day is that blue wavelengths scatter more in the atmosphere. But in our modern and digital world, we are also exposed to artificial sources: computer monitors, tablets, smartphones, LED lights, and flat-screen TVs. All of them emit large amounts of blue light. Sunlight has a mix of colors in it: Red, orange, yellow, green, blue, indigo, and violet light. Screens work with red, green, and blue (RGB pixels).
As you see, before considering it the enemy, we should understand that blue light is a natural and essential part of life. However, with modern technology flooding us with it at all hours, learning how it works and how to manage it has become a real challenge. Just think about it, every time you open your phone, scroll through your laptop, or binge-watch late into the night, you get sort of a “bath” in blue light and that invisible yet powerful force from the visible spectrum that has a bigger impact on your life than you might think.
How does blue light influence our bodies?
Blue light has more energy and a shorter wavelength, while light on the red side of the spectrum has less energy and a longer wavelength. As a reference for you to measure the power of blue light, Harvard researchers showed that indoor blue light suppressed melatonin twice as much as green light, shifting sleep onset by several hours. It means our bodies are very sensitive to the blue one. So the biggest dose of it, the one we receive daily from the sunlight, improves alertness, reaction time, memory, mood, and it controls our circadian rhythm. How does it work?
Alertness and blue light
Blue light has a direct neurological effect on the brain’s retinohypothalamic tract, a pathway that links the retina (in your eyes) to the brain’s suprachiasmatic nucleus (SCN), your internal clock. When blue light hits the photoreceptors in your eyes (specifically, intrinsically photosensitive retinal ganglion cells, or ipRGCs), it sends signals to the SCN, which then reduces melatonin production and boosts levels of cortisol and norepinephrine, hormones associated with alertness and energy.
As a result, you feel more awake, focused, and mentally sharp during the day, especially in the morning. That’s why natural morning sunlight is one of the best “natural stimulants” you can get. It works even better than coffee! You can learn more about this by listening to the Huberman Lab podcast.
Enhanced memory and blue light
Blue light does not just wake you up; it also stimulates areas in the brain responsible for working memory, particularly the prefrontal cortex. Studies using fMRI scans have shown that blue light exposure increases brain activity in these regions, improving executive function, the mental skills you use to remember, organize, and plan. Additionally, blue light indirectly supports memory by increasing alertness and attention span, which are essential for encoding information effectively. Think about it like if you are not mentally present, you are less likely to retain anything.
Then, you are more likely to absorb and recall information when exposed to natural daylight, making blue light a quiet assistant to your brain’s memory center.
Mood and blue light
Blue light also influences the production of serotonin, a neurotransmitter often called the “feel-good” chemical. The same ipRGCs mentioned earlier not only control melatonin but also signal the dorsal raphe nucleus, a region rich in serotonin neurons. When blue light hits the retina during the day, serotonin levels rise, improving mood and reducing the risk of seasonal affective disorder (SAD). In fact, light therapy that mimics the effects of blue light is a proven treatment for SAD and certain forms of depression.
This is how regular exposure to blue-rich sunlight helps regulate mood, keeping you mentally balanced and emotionally resilient.
Circadian rhythm and blue light
Your circadian rhythm is your 24-hour internal clock that governs when you feel awake and when you feel sleepy. It is primarily regulated by blue light through the SCN, which synchronizes bodily functions with the day-night cycle. Morning exposure to blue light signals the body to suppress melatonin, while diminishing blue light in the evening allows melatonin to rise, prepping your body for sleep. This rhythm influences everything in your body, from digestion to body temperature to cell regeneration, you name it!
So, proper blue light exposure during the day helps you wake up naturally, stay energized, and fall asleep on schedule, syncing your biological processes with the real world.
Here’s where it gets interesting: blue light is both good and bad. During the day, it helps a lot, but at night, excessive blue light confuses your body into thinking it’s still daytime, disrupting your sleep and possibly impacting your long-term health. Even dim artificial light at night can inhibit melatonin, with blue light creating twice as much suppression compared to green light. Suppressing melatonin affects sleep duration and quality, delaying deep sleep cycles. Compromised sleep cascades into daytime fatigue, mood changes, weakened immune function, weight gain, and higher risks of diabetes, heart disease, obesity, and even cancer, especially prevalent among shift workers and frequent travelers due to chronodisruption.
How does the blue light work on our eyes?
As for our eyes, there are lots of medical opinions. Some even point out risks like nearsightedness and macular degeneration (damage to the retina that causes loss of visual acuity).
But the debate about how much blue light is required to damage them irretrievably is still open. Let’s unpack the realities.
Eye strain and retinal damage
Digital eye strain or computer vision syndrome (CVS) is the most common consequence of screen use.
What we know is that the high energy and short wavelength of the blue light make it disperse more easily, so it is harder to focus it. It becomes “visual noise” that reduces contrast. Therefore, different symptoms of the CVS can appear (dry eyes, headaches, eyestrain and fatigue, blurry or double vision, neck or shoulder tension, etc.) due to reduced blink rate, glare, extended near-work focus, and poor ergonomics.
Different and recent studies, such as that of Mohamed Abdouh and others (2024), confirm that prolonged blue light exposure causes oxidative stress (via reactive oxygen species) in corneal and retinal cells, but that is at really much higher levels than typical screen usage. Lab studies show cellular damage only under intense, sustained blue light, much higher than what your phone or laptop emits. Based on these results, screen light has not been shown to directly produce lasting retinal damage. That is great news considering that blue light can be practically everywhere.
How do computer glasses work?
Computer glasses work by using blue-light filtering lenses, either with a clear, yellowish, or amber tint that block or absorb specific blue wavelengths, especially those around 455 nm (which most affect your circadian rhythm and visual strain). Some even include anti-glare coatings, which soften the harshness of artificial light.
Now we know that screens of phones, laptops, and TVs emit blue light, a short-wavelength, high-energy light in the 400–500 nm range. Your eyes are not great at blocking this kind of light. In fact, most of it goes straight through the cornea and lens into the retina. That is fine in small doses (like natural sunlight), but too much, especially at night, can mess with your overall visual comfort.
Therefore, lenses of computer glasses are crafted with special pigments or coatings that reflect or absorb part of the blue light spectrum, like this:
- Clear lenses often block 10 to 30% of blue light (better for daytime).
- Amber or red lenses block 60 to 90% (ideal for nighttime).
- Filters at 455 to 470 nm reduce melatonin suppression the most.
As you see, the anti-reflective coatings reduce the brightness coming from the screen and other sources of light we have around. Tints, like the popular yellow, improve the contrast and reduce the intensity of the light. Finally, blue-light blocking filters absorb or block the blue light that goes straight into your eyes.
As a result, wearing these glasses contributes to keeping your eye muscles more relaxed, reduces oxidative stress on retinal cells, and allows your brain to recognize nighttime, helping you sleep better.
So, should we wear computer glasses or not?
Yes, computer glasses protect our eyes. Choose the right ones based on your specific routine and needs. Their quality varies from brand to brand and depends on the materials used too.
Computer glasses optimize eyesight when we are staring at the screen. While reducing brightness and increasing contrast, the lenses maximize what we see. So our eyes suffer less from fatigue, and we can work longer in front of the screen. Now, you know that the technology to achieve this includes, basically, anti-reflective coatings, color tints, and blue-light filters. Look for that on the glasses’ specifications before you buy!
A healthy present and future for our eyes
The digital age we live in makes it unrealistic to completely avoid ‘screen time’. So, let’s protect our eyes as much as possible. Computer glasses are a choice, but also consider the following:
- Keep the brightness at acceptable levels. Don’t set it on a maximum level for long, and optimize the contrast to reduce glare.
- Keep your eyes at least 40 centimeters away from the screen. The bigger the screen is, the further your eyes should be from it.
- Give yourself breaks every 20 or 30 minutes. Relax your eyes by watching distant things or people. Close them for a few seconds.
- Blink often. When we are focused, we blink less. So blink to lubricate the eyeballs properly.
- Use the ‘night mode’ on your devices. It turns off the blue pixels and provides a warmer image.
- Minimizing blue light exposure at night using software like Night Shift or f.lux,
- Keep a good posture and use proper ambient lighting.
- Distinguish among symptoms caused by long exposure to screens and other factors with your doctor’s help. You might have vision problems that could worsen if not checked on time.
- Finally, screen time moderation is the best for your health. Balance the time you spend in front of the screen and reduce the risks.