Migraine Glasses

FL-41 Glasses vs Blue Blocking Glasses

FL-41 Glasses vs Blue Blocking Glasses

If you’re light sensitive, you’re probably on the lookout for ways to protect yourself from excessively bright light or blue light. Nobody could blame you, since light sensitivity can cause symptoms like migraine headaches, dizziness, nausea, burning sensation, and pain.

In your search for relief, you might turn to specially-tinted glasses, like blue blockers or FL-41. But what’s the difference between them, and is one better than the other?

In this article, we’ll compare FL-41 glasses vs blue blocking glasses. We’ll define them both with their benefits and drawbacks, and help you find the best solution for your photophobia.

What Are FL-41 Glasses?

FL-41 glasses were developed in 1991. Sometimes called migraine glasses, they were designed to help people ward off symptoms of sensitivity to fluorescent lights. Fluorescent lights put out a lot of blue light, which bothers a lot of people with photophobia. Today, many people who are light sensitive or get migraine headaches use them to filter out blue light and get some relief.

FL-41 lenses have a rosy tint. Made properly and precisely, this tint blocks some of the aggravating blue light from entering your eyes. This is probably why a lot of people talk about FL-41 glasses vs blue blocking glasses interchangeably. However, as you’ll learn by reading this article, they are not the same thing.

Benefits of FL-41 Glasses

FL-41 lenses have some potential benefits that are well-rooted in science.

  • The rosy hue of FL-41 glasses aims to block blue light, which peaks at 480 nanometers. Certain cells in the eye, called ipRGCs, are highly sensitive to this specific wavelength. So it’s pretty logical that filtering this wavelength could reduce your sensitivity.
  • If filtering this wavelength is enough for you, then FL-41 glasses might help to reduce your light sensitivity symptoms.
  • You may experience fewer headaches, less squinting, and an improvement in other symptoms while wearing them.

Potential Drawbacks of FL-41 Glasses

FL-41 glasses were a major breakthrough in treating light sensitivity, but we’ve learned a lot more about light sensitivity and its contributors since 1991.

FL-41 Doesn’t Block Amber Light

Over the last 30+ years, researchers have learned that blue light isn’t the only type of light that tends to bother photosensitive people, leading to symptoms including migraine headaches. They’ve figured out that both blue and amber light can aggravate photophobia. FL-41 glasses are designed to block the blue light, but not the amber light.

In short, you might get some relief from FL-41 glasses because they keep a good percentage of blue light from getting into your eyes. But you won’t get any relief from the offending amber light.

FL-41 Blocks the Helpful Light

Through research, doctors and scientists (including Axon Optics’ founder, Dr. Bradley Katz) have discovered that other types of light are actually beneficial or soothing to people who are light sensitive.

Green light is known to actually reduce photophobia and headache severity. Unfortunately, FL-41 lenses block 80% of it (see the chart below). Along with filtering the offending light, doesn’t it make sense that lenses purported to help you with light sensitivity should also let in the soothing light?

Gunnar Optics blue light lens spectrum measured on 08/02/21 on BPI Spectrometer.

FL-41 Glasses Are Inconsistent

There are a lot of companies that sell glasses labeled as FL-41. However, what you actually get when you buy glasses from these companies can vary significantly.

One study found major variations in lens color, quality, spectral characteristics, and optical densities between FL-41 lenses sold by different shops. See the images below for the data.

Each line of this graph represents an FL-41 lens from a different vendor. The lines show how much of various light wavelengths actually pass through the lens. You can see how big the differences are.

FL- 41 Glasses VS Blue Blocking glasses. FL-41 glasses vary widely in what they actually block.

The graphic below illustrates the real-world differences in lens color among FL-41 vendors. These photos were all taken of the same model in the same lighting. See how they vary from purple, to rust-colored, to hot pink?

When it comes to FL-41 glasses vs blue blocking glasses, even FL-41 lenses come with wide variances in color.

If FL-41 glasses are precisely made with the exact tint that blocks certain types of light, shouldn’t they all be the same? Clearly they’re clearly not. There is just no way to know exactly what you’re getting.

What Are Blue Blocking Glasses?

Blue light blocking glasses are frequently called blue blockers. They’re intended to reduce your discomfort by doing just what their name implies: blocking blue light.

Blue light comes from several sources, including LED and fluorescent lighting, and also from the sun. In this day and age, much of the blue light we’re exposed to comes from digital screens like computers, TVs, and smartphones.

You can buy blue light glasses from many traditional and online stores. When you get new glasses from your eye doctor, you might also be able to request a special coating that filters blue light.

Benefits of Blue Blocking Glasses

Some people swear that blue blockers help them avoid eye strain or improve their sleep. There could be some scientific evidence to support these claims.

  • In 2017, a study followed 80 computer users for one month, providing them with blue blocking lenses. At the end of the study period, one-third of them felt like the glasses were helpful, reducing glare and improving their ability to see clearly.
  • A limited study in 2019 studied healthy athletes who wore either blue blocking or transparent lenses for 3 hours before going to bed. Those who wore the blue blockers were able to get to sleep faster, but there was no total impact found on their wakefulness during the night.
  • In 2020, a study had bipolar patients wear blue blockers for 3 hours before bed. These patients usually had trouble sleeping, but during the blue blocker study they experienced better sleep efficiency and less wakefulness after falling asleep.

Potential Drawbacks of Blue Blocking Glasses

While blue blocking glasses are purported by many to help ease eye strain, there are mixed reviews and research as well.

They May Not Help With Eye Strain

A study released in 2021 states that blue light lenses may have no effect on eye strain symptoms. This study involved 120 eye-strain-symptomatic participants. After participants completed a 2-hour computer task, there was no significant difference reported in eye strain symptoms between those who wore blue blockers and those who wore the placebo.

They Haven’t Been Shown to Reduce Migraine or Light Sensitivity

In spite of many studies, blue blocking glasses haven’t been shown to help with symptoms of migraine or light sensitivity. This could be because a lot of blue blockers don’t block much blue light when tested, nor do they block much amber light. See the chart below for details.

Blue light blocking glasses don't block as much blue or amber light as Axon Optics.

Lens spectrum measured on 08/02/21 on BPI Spectrometer.

You Don’t Know What You’re Getting

Like FL-41 lenses, blue light blockers are inconsistent among makers. They actually vary quite widely in how much blue light they block, as you can see from the chart above. Unless you own a spectrometer to test them yourself, there’s no way to know what you’ve really got.

Notice that Axon Optics glasses block the most blue and amber light by far.

As shown in the following graphic, blue blockers also vary in lens hue. Just looking at the different hues of these lenses should tell you a lot about the inconsistency of blue blockers.

When it comes to FL-41 vs blue blocking glasses, the real comparison you should be making is with Axon Optics which block more blue and amber light and are always consistent. Blue light blocking glasses vary widely.

They Reflect Glare Into Your Eyes

Many blue blocking lenses don’t come with any anti-reflective coatings. For people who are light sensitive, this is a problem because it could result in painful light being reflected right back at you.

The graphic below shows what a difference these coatings can make. Some blue blockers reflect as much as 8% of that blue light back into your eyes. Notice the difference between the blue blocking lenses and the pair from Axon Optics.

Blue blocking glasses can reflect up to 8% of blue light back into your eyes.

So while blue blockers may indeed be helpful to some, the science is mixed and the quality could be questionable. Blue blocking glasses aren’t made to help you with photophobia or migraine, so they can’t be relied on for that.

Summarizing the Difference Between FL-41 Glasses vs Blue Blocking Glasses


FL-41 glasses are indeed backed by decades-old research. However, they only block blue light, and not the amber. To avoid discomfort, you need to block both blue and amber light.

Along with blocking blue and amber light, you need to let in the soothing green light to get the best relief. Unfortunately, FL-41 lenses also block the green light.

The consistency between brands is also a big question mark, making it tough to know if you’re really getting what you’re paying for.

Blue Blockers

While many users say blue blockers help their eyes feel better when using a computer, or even help them sleep better, the research is mixed. Positive studies of blue blockers are generally small.

Unlike FL-41, blue blockers aren’t designed to help people with photophobia and migraines, and have never been shown to have that benefit.

And just like FL-41 glasses, the quality and effectiveness of blue blocking glasses vary widely from maker to maker.

The Axon Optics Difference vs FL-41 and Blue Blockers

As stated above, for maximum relief from light sensitivity and migraine, you need to block both blue and amber light, plus allow the soothing green light in. This is exactly what Axon Optics migraine glasses are engineered to do.

Our founder, neuro-ophthalmologist Dr. Bradley Katz has been hard at work since the 1990s to improve the FL-41 tint, increasing its effectiveness for people with photophobia and light-triggered migraines.

Under his leadership, Axon Optics has made significant improvement to FL-41 glasses, and the results are well documented.

  • 85% of Axon Optics users experience reduced symptoms of light sensitivity, including migraine attacks
  • Axon Optics block more blue and amber light, both shown to aggravate photophobia
  • Axon Optics lenses allow in 2.5x more soothing green light
  • Less than .2% glare due to advanced coatings
  • Every lens is the same, with consistent quality and effectiveness
  • 18 protective coatings and high quality frames

Axon Optics continues to do research and improve our lenses when science supports it. If you’re on the fence about FL-41 glasses vs blue blocking glasses, consider our glasses for migraine and light sensitivity. They block more of the bad light and let in more of the good — every pair, every time.

FL-41 glasses vs blue blocking glasses — the real comparison is with Axon Optics

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