How much blue light should my glasses block?

When we talk about blue light, it’s important to understand that it isn’t a single type of light but rather a spectrum stretching from 380 to 495 nanometres. The light at the higher end of this spectrum is the part that can be most disruptive to our sleep and overall well-being.

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What is blue light?

Blue light is part of the visible light spectrum, and it’s the part with the shortest wavelengths and the highest energy. Blue light comes from many sources, including the sun, LED lighting and digital screens.

The benefits of 30% blue light glasses

Blue light glasses that block 30% of blue light are a good middle-ground option. They offer a moderate amount of protection without dramatically changing how colours look on your screen — making them a sensible choice for daytime use, when you still want a natural visual experience while reducing some of the strain. They’re well suited to people who spend regular but not extreme amounts of time in front of screens, and who want to limit the build-up of digital eye strain.

The benefits of 90% blue light glasses

At the other end of the scale, 90% blue light blocking glasses are designed to give the maximum amount of protection. These can be a good choice if you’re particularly sensitive to blue light, or if you spend a lot of time in front of screens — especially in the evening. Research has shown that too much exposure to blue light can disrupt sleep by suppressing the production of melatonin, the hormone that helps us drift off.

How to choose between 30% and 90% blue light glasses

When you’re choosing between 30% and 90% blue light glasses, it’s worth thinking about your individual needs and lifestyle. To make that easier, here are a few factors that can help you make the right call.

30% blue light glasses:

You spend a regular but moderate amount of time in front of screens during the day.
You want a balanced reduction in blue light exposure without a noticeable change to how colours look on your screen.
You’d like a small but consistent step toward less digital eye strain over the course of a working day.
You’re after a more discreet option that fits naturally into your daily routine and your workplace.

90% blue light glasses:

You’re particularly sensitive to blue light and experience symptoms like trouble sleeping, eye irritation or headaches.
You spend many hours in front of screens, especially in the evening, and are concerned about how that’s affecting your sleep.
You’re willing to accept a noticeable change in colour rendering in exchange for maximum blue light protection.
You’re looking for a solution targeted at intensive screen time and want to minimise the risk of long-term eye issues.

To sum up: 30% glasses are a great everyday option for moderate use, while 90% glasses are made for people who really need maximum protection — most often for use late in the evening, before bed. Whichever pair fits you best, you’ll be reducing your exposure to blue light, protecting your eyes, and helping your sleep quality.

Shopping for blue light glasses

When you’re shopping for blue light glasses (we offer them without prescription), there are a few things worth considering. First — how much blue light do you want to block? If you only want to reduce exposure a little, choose glasses that block around 30%. If you want to minimise it as much as possible, especially in the evening, choose 90%.

Frequently asked questions

Do blue light glasses actually work?

Yes — blue light glasses help reduce your exposure to blue light, which can lower digital eye strain and support better sleep. If you spend a lot of time in front of screens, especially in the evening, wearing blue light glasses can be a real help.

Is all blue light harmful?

No. Blue light is natural and necessary for our circadian rhythm and overall well-being. The problem starts when we’re exposed to too much of it — particularly from artificial sources like digital screens, and especially close to bedtime.

Can blue light damage my eyes?

Long-term exposure to blue light from digital screens can lead to digital eye strain, with symptoms like dry eyes, fatigue and headaches. Some studies suggest that excessive blue light may contribute to more serious eye issues over time, but more research is needed in this area.

Can I get blue light glasses without prescription lenses?

Yes — you can get non-prescription blue light glasses. They’re designed specifically to block blue light and can be worn by people without vision issues.

How often should I wear my blue light glasses?

It depends on how much time you spend in front of screens. If you’re working on a computer all day, it’s a good idea to wear them during work. If you only use screens occasionally, you may only need them in those moments. It’s especially worth wearing them if you’re using screens in the evening, since blue light can disrupt your sleep.

Choosing the best blue light glasses

The choice between 30% and 90% blue light glasses depends largely on your individual needs and how you use screens. Both 30% and 90% blue light glasses are great choices, depending on what you’re trying to achieve. If you’re considering a pair, take into account your screen time, your sensitivity to blue light, and your daily routine. And remember — taking regular breaks from your screen is always a good idea to give your eyes a rest.