Making Sense of Blue Light and Our Vision

October 22, 2020
Eye Health

We’re keeping it simple. Here’s how screens impact your eyes and what you should look for in blue light filtering lenses.

If you’ve spent any time looking for new glasses recently, you’ve probably seen ads promoting blue light filtering lenses to protect your eyes from screens. 

It’s unsurprising these brands have taken off. Modern worklife—with its barrage of emails, DMs, and Zoom calls—plus the rapid fire nature of news and social media all push us to spend more time than ever in front of our screens. 

As a level-set, the same blue light that backlights our digital devices is ever-present in the natural world. Its most abundant source is sunlight, and in small doses blue light is proven to have positive impacts. That being said, our eyes aren’t built for the amount of time we spend in front of screens. 

So what does all of this mean? Below, we broke down some of the most commonly asked questions on blue light and digital eye strain—including what to look for if you do opt for blue light glasses.

How does blue light affect our eyes and our bodies as a whole–both positively and negatively?

Small amounts of exposure to blue light can actually have positive effects on our sight and bodies. Here’s how:

  • Decreased nearsightedness: Sunlight exposure has been shown to improve nearsightedness and decrease astigmatism. 
  • Better mood and cognitive function: Blue light aids in regulation of our body’s natural clock, promotes alertness, and can even improve memory. This type of light can also boost our mood, and is used as a therapeutic treatment for seasonal affective disorder. 

However, when we’re overexposed to blue light–through phones, laptops, tablets, and TVs–we can incur harm. Here’s what happens:

  • Disrupted circadian rhythm and sleepBlue light exposure after dark mimics sunlight. This causes a decrease in melatonin production, resulting in insomnia and/or difficulty sleeping. Research shows that poor or insufficient sleep increases the risk for health conditions like obesity, diabetes, cardiovascular disease, ADHD, anxiety, and depression.
  • Eye disorders: Overexposure to blue light may be an underlying cause of dry eye and may also play a role in cataract formation, along with the increased potential risk for age-related macular degeneration.
  • Digital eye strain: Extended exposure to this light can have negative effects including blurred vision, insomnia, and eye fatigue associated with a condition called digital eye strain.
I’ve seen experts say there’s no evidence that the amount of blue light emitted from screens is harmful to our eyes. Is this true?

There’s still discussion in the scientific community on the long-term effects of blue light. Key studies confirming retinal cell death after exposure to blue light have been conducted on rat and primate retinas, not human ones, which leaves the findings open to scientific debate. Additionally, the amount of blue light emitted from our digital devices is much lower than the threshold commonly tested, and not as likely to cause permanent damage.

While there’s debate on long-term effects, we can all agree that increased exposure to digital devices can cause digital eye strain in the short-term. An estimated 59% of Americans experience at least one of the following after two hours of screen time: eye strain, headache, light sensitivity, blurred vision, dry eyes, or neck/shoulder/back pain. Often patients don’t even realize that screen exposure is the cause of these symptoms.

Limiting screen time is the easiest solution, but for so many of us, the overexposure from our devices is part of the daily reality of our jobs and life. Fortunately, there are other steps we can take to protect our eyes as we spend time on our devices. The best place to start? A pair of blue light filtering glasses.

How do blue-light-blocking lenses work, exactly? Are there studies that show they’re truly as effective as people claim they are?

Blue-light reducing technology works in one of two ways—blocking or filtering. Glasses that block blue light effectively block all blue light (specifically in the 400-495nm range) but have a noticeable yellow tint. Think 1990s BluBlockers.

In recent years, technology has progressed, so blue light filtering technology can be embedded within or applied directly to the lens, allowing the lens to remain clear while still reducing the transmission of harmful blue light. As you might expect, this approach is much more popular. A recent study found that blue-light filtering lenses successfully decrease the amount of blue light entering the eye and serve as an effective supplementary option to protect the retina from the potential blue-light hazard.

What should I look for in blue light glasses? Is there anything I should avoid in blue light glasses?

We always recommend that customers pay attention to the percentage of blue light being filtered. We ordered several “blue light protection” lenses from multiple online companies and labs in the Los Angeles area and were shocked to find many were ineffective. Blue light transmittance analysis reports on the lenses showed efficacy rates as low as 15%—meaning that 85% of blue light was passing through the lens! 

For the best quality, we recommend speaking directly with optometry offices and optical retailers because of their access to premium blue-light filtering lenses and coatings.

What else can I do to take care of my eyes throughout the day?

There are several things you can do to protect your eyes. Wearing sunglasses outside will protect you from harmful ultraviolet rays and decrease the amount of blue light entering the eye. Additionally, eating a diet full of dark leafy greens is important because they contain the antioxidants lutein and zeaxanthin. Lutein and zeaxanthin are carotenoids found in healthy eyes that help to protect against ultraviolet and blue-light damage. 

I wear blue blocking lenses myself, and my team at Zak. and I prescribe them to our patients. They’re at the ready whenever I spend extensive time in front of the screen. And you’re likely to find kale or spinach as frequent, eye-friendly, ingredients in my lunches. These are preventive and holistic solutions, ones that actually integrate well with modern living.

In 2018 Kyly Rabin and her father, an optometrist, co-founded Zak with the goal of bringing a fresh vision to the optical industry. Drawing on her background in startups and her father's history treating patients, the two were able to build a high-quality, health-focused, and comprehensive eye experience by making a typically complicated journey more seamless. Rabin leads Zak’s operations, recruiting best-in-class optometrists, designing customer experience, and overseeing Zak’s in-house collection of exclusive frames and same-day fabrication in Zak’s on-site lab.



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