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Are blue-light glasses effective?

What is blue light? How does blue light affect my eyes? Do i need glasses to block blue light?

Ankush Datar
5 min read • 
3 June 2023

Editor’s Note: First of all, thank you! Wow! I was absolutely blown away by the overwhelming response from all of you amazing readers on our call for feedback. So many ideas. Your flood of emails truly touched us and filled us with even more excitement for what we do. 

I’ve managed to respond to around a hundred emails so far, but there are still many more to go. Rest assured, we’re working hard to get back to each and every one of you very soon. You deserve our undivided attention, just as you’ve given us yours. 

Now, onto today’s piece: Our regular contributor Ankush Datar (here is a link to his Twitter and Substack) dives into the buzz around blue-light blocking glasses. Should you consider getting a pair? He breaks it down while explaining the impact of light on our health. If you’re reading this on your phone at night… well, you definitely need to read this. Or maybe not? 😉

Screens are taking over our lives. We’ve all heard the warnings: “Put down your phone!” or “Get off the computer!” 

We know we should be outside, soaking up the sun and “unplug.” 

But in our modern age, where every new concern breeds anxiety, companies swoop in, ready to sell the latest product to alleviate our worries. So following the pattern, a product was born for the screen-obsessed eyesight-concerned around us: the blue-light blocking glasses. 

You know them, right? The specialised eyewear designed to filter out or reduce the amount of blue light that reaches your eyes? 

But what is blue light? And they do what? Why do we want to block them? And do we need those fancy glasses?

Let’s talk about that. 

And also, let’s understand the role of light on our overall health — which we don’t often factor in everyday discussions on fitness. 

Start with a quick high-school physics refresher: The light spectrum has different colours with their own wavelengths. So at one end, we have red and orange light, with long, spaced-out waves, and then on the other, we have violet and blue light with shorter, closer waves. 

Longer wavelengths, like red and orange, feel warm and calming, like cosy settings or sunset. They help us relax. 

Shorter wavelengths, such as blue light, have a stimulating effect during the day. They help to increase alertness, enhance cognitive function, and uplift our mood.

Natural light consists of a balanced spectrum of colours, including different intensities of red, orange, yellow, green, blue, and violet light.

Thousands of years of evolution have shaped the human body to thrive with regular exposure to natural light. We evolved watching the sunrise, spending our days outdoors, and then sitting and observing the sun as it sets. 

This natural light pattern has higher intensities of bright, blue-rich light in the morning and dim, red-rich light in the evening. And this pattern synchronises our circadian rhythm, the internal clock that regulates our sleep-wake cycle and various physiological processes. Our circadian rhythm tells our body when it’s time to be awake and alert and when it’s time to wind down and sleep.

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Meet Melatonin

While we bask in the glow of light around us, something is happening inside us which is also significant — it’s the production of a hormone called melatonin, which is intricately connected to light. 

When exposed to darkness, our brain receives signals to increase melatonin production, signalling that it’s time to prepare for sleep. Conversely, exposure to light, mainly blue light, can suppress melatonin production, signalling the body to stay awake and alert. 

This connection between melatonin and light underscores the importance of managing our light exposure, especially in the evening, to support a healthy sleep-wake cycle.

This is what has changed: the modern world drastically altered our light environment. 

We are surrounded by artificial light during the day and night.  From the moment we wake up to when we go to bed, we are constantly exposed to the glow of screens, fluorescent bulbs, and LED lights.

This has increased our exposure to blue wavelengths, which becomes concerning in the evening. 

That’s because the blue light emitted by electronic devices and certain indoor lighting in the evening suppress melatonin production. Blue light mimics natural daylight and tricks our brains into thinking it’s still daytime. So our internal clock is confused and signals to our bodies to stay awake when it’s time to wind down instead.

And then we struggle with sleep. 

This was not always the case. 

“The light emanating from electronic devices was not always such a hindrance to restful sleep,” says the Scientific American

The current state of affairs can be traced to the 1992 invention in Japan of the high-brightness blue LED. By combining the new blue LEDs with older green and red ones or coating blue LEDs with chemicals that reemit other wavelengths, technology manufacturers could generate full-spectrum white LED light for the first time. 

Because LEDs are much more energy-efficient than their fluorescent predecessors, they soon became ubiquitous in TVs, computer screens, tablets and certain e-readers, infusing homes and offices with much brighter blue light than ever before.

So to summarise: Screens surround us, screens are emitting more and more blue light, and blue light exposure, especially in the evening, suppresses our melatonin levels and then THIS hinders good sleep

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So is there a solution for our eye-health and sleep-health?

Marketers in this world will tell you that there is. Enter blue-light blocking glasses which typically feature lenses with a special coating or tint, selectively blocking or absorbing blue light wavelengths. 

They can help, but the issue is overselling. So let’s make things clear:

1. Blue-light glasses might make it easier to fall asleep

With the logic explained above, good quality glasses that block a good deal of the blue light your eyes are exposed to, especially during the evening, might help you with sleep troubles. 

But beware: it’s important to note that just wearing blue-light glasses does not entirely eliminate the sleep-disrupting effects of blue light exposure; they can only help reduce its impact.

That’s why I bought them, and they helped me, as I explained in my previous article on improving sleep

But you don’t necessarily have to. There are more straightforward ways. 

a) Avoid screens and bright lights for 1-2 hours before sleep.

b) Reduce smartphone screen brightness which can stimulate the eyes and suppress melatonin production.

c) Activate the screen features that reduce blue light emission, available on most smartphones: “Night Mode” on Android or “Night Shift” on Apple.  Schedule it to activate automatically in the evening. 

So be conscious. Look at sources of blue light, try reducing exposure to those sources in the evening, and still, getting these glasses is an option if you are having trouble with sleep. 

(Editor’s note: As a publication, we are not endorsing or rejecting the idea of purchasing blue-light glasses for better sleep. If you would like to explore this topic further and understand whether it is beneficial to buy them, we recommend referring to this excellent guide by The New York Times.. We encourage you to check with your doctor if you are considering getting blue-light glasses!) 

2. Blue-light glasses are unlikely to prevent eye-strain or eye-damage

That’s because the blue light emitted by electronic devices does not increase the risk of macular degeneration or harm any other eye part. 

As the NYT guide notes

Eye experts say the low levels of blue light from your computer screen probably aren’t making your eyes tired and achy—it’s more likely that while intensely focusing on your screen, you blink less, resulting in dryer eyes. 

This can lead to digital eye strain, and potentially blurry vision, dry eyes, and headaches. It’s similar to how you might feel after periods of intense focus, such as reading a book. 


But this is a claim often used to sell these glasses — and the one you should watch out for. 

In the United Kingdom, Boots Opticians faced a fine of £40,000 for making “misleading and unsubstantiated” claims regarding the ability of blue-light glasses to protect the retina from damage.

The American Academy of Ophthalmology (AAO) agrees: “there is no scientific evidence that the light coming from computer screens is damaging to the eyes. Because of this, the Academy does not recommend any special eyewear for computer use.”

The AAO instead recommends the 20-20-20 rule: Every 20 minutes, look at an object 20 feet away for 20 seconds to alleviate eye strain caused by screen use.

Hope this makes the buzz around these glasses clear. 

I will end with a quick note on seeking natural light: Maximising morning sunlight enhances nighttime sleep quality. So consider incorporating a short walk or bike ride into your morning routine, as daytime exercise promotes better sleep. And even on cloudy days, stepping outside is beneficial: grey skies still provide approximately four to five times more light than indoor artificial lighting. 

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