Polarized vs. Non-Polarized Sunglasses for Mountain Biking
"Polarized lenses are #1 cause they reduce glare and ease eye strain!"
"Bruh... polarized lenses mess with yer depth perception."
Let's talk about a common debate among some mountain bikers. No, we're not talking about shaved legs vs hairy - we'll cover that topic later. This one revolves around your eyeballs and whether polarized, or non-polarized lenses are the ideal choice. Let's cut to the chase and separate fact from fiction.
Polarized and Non-Polarized Lenses - What are They?
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Polarized Lenses feature a special chemical film that filters out horizontally polarized light, reducing glare from reflective surfaces like water, snow, or glass. However, their use in sports like mountain biking has sparked some debate due to potential drawbacks related to depth perception and contrast sensitivity
- Fun fact: polarized lenses were originally developed by NASA for astronauts. Far out!
- Non-Polarized Lenses don't have the glare-reducing filter and instead uniformly reduce light intensity across all wavelengths. They often come with UV protection and various tint options but don’t specifically target glare.
Key takeaway: Polarized lenses reduce light glare on horizontal surfaces (aka flat stuff), but those flat features usually aren't prevalent in the mountains. Take it from these smart people at Harvard:
"When sunlight hits an uneven surface, it scatters in multiple directions. This does not typically affect your ability to see clearly. But when light hits even surfaces — like a pond, a flat road, or a snow-covered ski slope on a sunny day — the light doesn't scatter. Instead, it is reflected in one direction, causing glare and reducing depth perception."
https://www.health.harvard.edu/staying-healthy/polarized-sunglasses-protecting-your-eyes-from-harmful-glare
Do Polarized Lenses Really Impact Depth Perception?
- Limited Direct Studies: There’s no widely cited, recent study specifically testing polarized lenses’ impact on depth perception in mountain biking. The only study we could find was from 2008, done by ADS Sports Eyewear, which tested polarized lenses across sports, including biking. It found no adverse effect on depth perception with high-quality polarized lenses, suggesting that lens quality matters more than polarization itself. They noted improved contrast enhanced depth perception for motorcyclists and golfers, but mountain biking’s dynamic, close-range demands weren’t directly addressed. We'll let you judge if you trust that study or not.
- A 2023 study from the National Institutes of Health (NIH) on polarized filters in road sports measured spectral characteristics and road radiance. While focused on road biking, it didn’t find significant depth perception issues. But, it did show how polarization can mess with certain visual cues (e.g., strains in materials), which could apply to MTB trail features like wet roots or rocks.
Depth perception relies on differences between left and right eye images (aka binocular disparity) and monocular cues (e.g., shading, size). Polarization filters horizontal light, which might reduce subtle shading cues on uneven surfaces, theoretically flattening the visual field. Keep in mind - this effect varies by individual and lens quality, and no quantitative data proves a significant impact in biking contexts.
Dang. That was probably way more than you wanted to know.
Other Potential Drawbacks of Polarized Lenses
Two other notable factors to consider with polarized lenses are shaded areas and LCD screens.
- Evidence: User feedback from biking communities (e.g., MTBR forums) highlights that polarized lenses can make it harder to see in dense forests or under tree canopies, where glare is minimal but contrast is vital.
- Solution: EO specializes in light-adaptive photochromic MTB sunglasses. Shameless plug.
Limitations of Non-Polarized Lenses in Mountain Biking
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Susceptibility to glare: In bright sunlight or open areas with reflective surfaces, non-polarized lenses may cause eye strain due to unfiltered glare
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Limited utility in water-based activities: These lenses are less effective at reducing glare compared to polarized options.
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So if you road bike in the same sunnies as your MTB rides, and also experience frequent eye strain due to bright light, wet roads, or riding near water, you might consider polarized lenses.
What About Photochromic Lenses?
Glad you asked! Photochromic lenses automatically adjust their tint based on ambient light conditions and UV intensity. These bad boys can strike a balance between glare reduction and depth perception, making them a popular choice among mountain bikers who ride in varying environments. They usually are not polarized, so don't count on them to also provide the same level of glare reduction as polarized lenses.
Factors to Consider When Picking Your Lens Type
As you might suspect, the 'right' answer depends on your individual preferences and riding conditions. Key factors include:
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: Riders who frequent shaded trails should prioritize depth perception over glare reduction.
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: Those exposed to intense sunlight may benefit from photochromic or lightly tinted non-polarized lenses.
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: Do you frequently use your MTB sunglasses also for cycling on flat roads with lots o' sun glare? Polarized might be your best bet.
Comparison Chart: Polarized vs. Non-Polarized for Mountain Biking
To visualize some of the trade-offs, here’s a handy-dandy comparison chart based on key factors for our MTB friends:
| Feature | Polarized Lenses | Non-Polarized Lenses |
|---|---|---|
| Glare Reduction | Excellent (up to 99%) | Poor |
| Depth Perception | Reduced | Preserved |
| Low-Light Performance | Poor | Good |
| Screen Compatibility | Poor (distorts some LCDs) | Excellent |
| Contrast Enhancement | Moderate (with tint) | High (with specific tints) |
| Cost | Higher ($50-$150+) | Lower ($20-$100) |
| Best For | Open, reflective trails | Technical, shaded trails |
Sources: SportRx (2021), Revant Optics (2022), Cyclists Hub (2023)
Conclusion: Are Non-Polarized MTB Sunglasses Your Best Bet?
Hot take: Contrast is a much more important aspect than polarization. If glare is your primary issue, and for most mountain bikers it is not, then go polarized. If contrast and depth perception are a bigger deal, non-polarized lenses will likely serve you quite well.
Usually there is very little glare out on the trail, and the effect on depth perception can cause you to not notice that root or prairie dog hole until it's too late.
Keep in mind that some riders with light sensitivity (e.g., in high-UV areas like here in Utah) may still prefer polarized lenses despite the drawbacks, as one r/MTB user noted: “I need polarized sunglasses everywhere I go” (Reddit, 2021).
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Sources:
https://www.health.harvard.edu/staying-healthy/polarized-sunglasses-protecting-your-eyes-from-harmful-glare
https://www.aao.org/eye-health/ask-ophthalmologist-q/will-polarized-lenses-affect-my-depth-perception
https://www.ncbi.nlm.nih.gov/books/NBK592424/
https://www.sportrx.com/blog/polarized-cycling-lenses/#are-polarized-cycling-glasses-right-for-you?