How Do Blue Light Blocking Lenses Work?

Our lives are increasingly digital. And, if you’re like most people, a large part of your day probably involves staring at screens.

Digital LED screens emit blue light. When you use your smartphone or your laptop, you’re being exposed to high-energy visible light.

Unfortunately, our eyes aren't really designed to handle blue light exposure at such close proximity, and for extended periods of time. In fact, studies show overexposure to blue light may be linked to eye strain, increased risk of macular degeneration, and sleep cycle disruption.

One of the ways that you can reduce your exposure to blue is by wearing glasses with blue light blocking lenses.

How do blue light blocking lenses work?

In order to understand how blue light blocking lenses work, first let's have a quick recap on how light works.

It’s all around us but what is light?

It may sound surprising but light is actually a form of electromagnetic radiation. It's why too much exposure to direct sunlight can trigger skin cancer.

Electromagnetic radiation exists as waves. These waves each have their own wavelengths measured in nanometers (nm). Collectively, the range of these different wavelengths is known as the electromagnetic spectrum.

 

 Above: A diagram showing the electromagnetic spectrum

Visible light is just a part of the electromagnetic spectrum, which also comprises radio waves, microwaves and X-rays.

A typical human eye responds to wavelengths from about 380 to 740 nanometers. We often call this part of the electromagnetic spectrum, the visible light spectrum.

To see anything we need light. The electromagnetic waves within the visible light spectrum are the waves that our eyes and brain process and turn into what we see around us.

Why we see different colors (and blue light)

Different wavelengths within the visible light spectrum represent different colors. The longest wavelength of light that humans can see is red. The shortest is violet. Ultraviolet (UV light) has an even shorter wavelength, but we can’t see it.

When light shines on an object some wavelengths bounce off the object and others are absorbed by it. Our eyes only see the wavelengths that are bounced off or reflected.

Blue light that screens emit sits in the upper end of the visible light spectrum: it has a short wavelength so it is higher-energy. It is why prolonged exposure to blue light from screens can irritate our eyes.

Although blue-violet light has less energy than ultraviolet light, it is almost entirely unfiltered as it passes through the eye and reaches the retina. By way of contrast, ultraviolet light is almost entirely absorbed by the front part of the eye, and significantly less than 5% of it reaches as far as the retina.

 

 

A red shirt looks red because the dye molecules in the fabric have absorbed the wavelengths of light from the violet/blue end of the spectrum. Red light is the only light that is reflected from the shirt. An object that reflects all frequencies will appear white. An object that absorbs all light will appear black.

So, how does this relate to blue light blocking lenses?

Blue light filter lenses are designed to filter out blue the high-energy blue light frequencies from the visible light spectrum. LUMES lenses are specially engineered to filter some of the highest energy wavelengths of visible light (400-440 nm).

LUMES lenses are virtually clear (with a barely noticeable yellow tint) which means color temperature is not affected perceptibly - which is especially important if you do something like graphic design where you need to see colors as they really are.

You don't actually need to block 100% of blue light since it’s required to regulate your natural wakefulness. Exposure to some blue light during the course of the day can help you maintain a natural circadian rhythm.

LUMES lenses block enough blue light to help your eyes feel more relaxed while allowing some exposure so your wake / sleep cycle can remain healthy.

 

How can blue light blocking lenses help you?

Blocking all light from our lives would be harmful. So how much do we need? And at what point in the day do we need to stop so we can prevent ourselves from overexposure?

Blue light blocking lenses can help to alleviate a variety of symptoms associated with prolonged screen use. We've listed the main ones below.

Better sleep

Blue light tells our body when we need to be awake. That's why looking at screens during the evening can interfere with the production of melatonin, the chemical responsible for helping you sleep.

Studies show that blue light blocking lenses can help you maintain a normal circadian rhythm, and help you get better quality sleep.

Computer eye strain

Our eyes muscles have to work harder to process text and images on screens because it is made up of pixels. Your eyes react to changing images on the screen to create so your brain can process what you’re seeing. All these jobs require a lot of effort from your eye muscles. Unlike paper, the screen adds contrast, flicker, and glare, which makes our eyes work even harder.

LUMES blue light blocking lenses also come with an anti-reflective coating. This helps to make your eyes feel more comfortable by reducing the glare that monitors create. 

Reduced risk of macular degeneration

In the same way that UV light can harm our cornea and skin, there are more and more studies are linking an overexposure of blue light to macular degeneration.

The macula is part of the retina. It's a crucial part of our vision and without it, we cannot see. There are eye doctors that believe the overexposure to blue light, due to our dependency on digital devices, can damage our retina. Some of them reference the growing number of macular degeneration cases, as well as the fact that people now develop it at younger ages.