High Altitude Sunglasses: UV, Snow and Mountain Conditions (2025)

High Altitude Sunglasses: UV, Snow and Mountain Conditions

The temperature drops as you climb. The air thins. And the UV goes up. These three facts together describe the fundamental paradox of high-altitude outdoor activity: the conditions that feel milder than a summer beach day are delivering more UV than that beach in July. At 10,000 feet on a Colorado ski slope, the combination of altitude UV amplification and snow surface reflection creates one of the most intense UV environments humans voluntarily enter.

Most people who ski, hike at altitude, or recreate in mountain environments understand vaguely that UV is intense at altitude. Very few understand the specific physics, the actual UV Index values at typical recreational altitudes, how snow reflection compounds the altitude effect, or what lens category this genuinely requires. This guide covers all of it.

This is a C21 Geography & Climate supporting post. It links back to the cluster pillar atsunglasses by climate and geography: the complete US regional guide.

Quick Answer

UV400 Category 3 for most mountain hiking and outdoor activities above 5,000 feet. Category 3–4 for skiing, snowboarding, and extended alpine snow environments at typical ski resort elevations (8,000–12,000+ feet). Category 4 for glacier crossings, extreme high-altitude mountaineering, and extended time on highly reflective snow at peak UV hours. Gray polarized for driving mountain roads and all-conditions versatility. Amber or rose for flat-light overcast ski and snow conditions. Goggle format for skiing and snowboarding — not eyeglass sunglasses.

•1. How Altitude Increases UV: The Physics

•2. UV at Typical US Recreational Altitudes

•3. The Snow Reflection Multiplier

•4. The Combined Effect: Altitude Plus Snow

•5. Why the Air Temperature Misleads

•6. US High-Altitude Recreation Locations

•7. Lens Category at Altitude

•8. When Category 4 Is Appropriate

•9. Goggle vs Eyeglass Sunglasses for Skiing

•10. Tint Choice for Mountain Conditions

•11. Driving Mountain Roads

•12. Summer Hiking at Altitude

•13. Year-Round Alpine UV

•14. Comparison Table

•15. Best For

•16. Common Mistakes

•17. Bottom Line

•18. FAQs

Part 1: How Altitude Increases UV — The Physics

UV radiation from the sun must pass through the atmosphere before reaching the ground. The atmosphere contains ozone, water vapor, aerosol particles, and air molecules that absorb and scatter UV. The thicker the atmospheric column the solar beam passes through, the more UV is attenuated before it reaches the surface.

At sea level, the full depth of the atmosphere is between the sun and the eye. At altitude, a significant portion of the most UV-absorptive lower atmosphere is below the observer. Less atmosphere between the sun and the eye means less UV attenuation. More UV arrives at the surface per unit of solar radiation at altitude than at sea level under identical sun angle conditions.

The quantified relationship: for every 1,000 feet of altitude gain, UV intensity increases by approximately 3–4%. This is a compounding increase. At 5,000 feet (the elevation of Denver), UV is approximately 15–20% more intense than at sea level. At 10,000 feet (a typical ski resort mid-mountain), UV is approximately 30–35% more intense. At 14,000 feet (Colorado’s Fourteeners, many accessible to recreational hikers), UV is approximately 40–45% more intense than at sea level.

Part 2: UV at Typical US Recreational Altitudes

Elevation	Location Examples	UV vs Sea Level (same latitude)	Effective UV Index (July noon, CO/UT latitude)
Sea level (baseline)	Miami, FL; Corpus Christi, TX	Baseline	9–11 (very high–extreme)
5,280 ft (1 mile)	Denver, CO; Reno, NV	~+15–20%	10–12 (extreme)
6,000–7,000 ft	Taos, NM; Flagstaff, AZ; Park City base	~+18–25%	10–12+ (extreme)
8,000–9,000 ft	Breckenridge base; Aspen base; Santa Fe	~+24–32%	11–13+ (extreme)
10,000 ft	Breckenridge mid-mountain; Vail peak	~+30–35%	12–14+ (extreme)
12,000–14,000 ft	Arapahoe Basin summit; CO Fourteeners	~+36–45%	13–15+ (above extreme scale)

These values are before snow reflection is added. They represent direct UV from the sky alone at altitude. Snow reflection on top of these values produces total UV exposure significantly above what any standard UV Index scale was designed to measure as a single-number ground-level estimate.

Part 3: The Snow Reflection Multiplier

Snow is one of the most reflective natural surfaces on Earth for UV radiation. Fresh snow reflects 85–95% of the UV that strikes it. Old, compacted ski resort snow reflects 50–80%. Ice reflects up to 80%.

This reflection is upward. A skier or hiker on snow receives UV from two directions simultaneously: directly from the sun and sky above, and reflected upward from the snow surface below. The UV reaching the eye is not just the overhead direct UV — it is overhead direct UV plus reflected UV from below and around.

The specific vulnerability this creates: the lower eyelid, the underside of the nose, and the skin directly beneath the eyes receive reflected UV from below that sunglasses with standard frame geometry do not shade. This is why alpine climbers and glacier trekkers traditionally use side-shielded glacier goggles — the reflected UV from the snow surface enters from below and from the sides in ways that require coverage beyond standard sunglass frames.

Part 4: The Combined Effect — Altitude Plus Snow

Adding altitude UV amplification to snow surface reflection produces UV conditions that can exceed what any standard UV Index value suggests for the latitude. Consider a skier at Breckenridge, Colorado in March:

• Latitude (39°N):March clear-sky UV Index at sea level approximately 5–6.

•Altitude adjustment at 10,000 ft:+30–35% = effective UV Index 7–8 from sky alone.

• Snow reflection (fresh snow, 85–95%):adds reflected UV from below approximately equal to 85–95% of the direct sky UV.

•Combined exposure:direct UV (UV Index 7–8) plus reflected UV (nearly equal again from fresh snow) = total UV exposure equivalent to UV Index 13–15, above the extreme category ceiling.

A March Breckenridge ski day delivers UV exposure comparable to or exceeding a July midday at a tropical beach, despite air temperatures in the 20–30°F range. Cold does not attenuate UV. Snow does not block UV — it reflects it. The skier who does not wear UV400 Cat 3–4 eye protection on a Colorado ski day is accumulating extreme UV exposure in conditions that feel cold enough to seem safe from sun damage.

Part 5: Why the Air Temperature Misleads

The intuitive association between warmth and UV risk is almost exactly backwards at altitude. The mechanisms:

• Cold air has less water vapor:water vapor absorbs some UV. Cold mountain air is dry and provides less atmospheric UV absorption, not more.

• Snow reflects UV upward:a warm beach day has sand (15–25% UV reflection). A cold ski day has snow (85–95% UV reflection). The cold day’s reflective surface is far more UV-intense than the warm day’s.

• Cool temperatures extend outdoor time:heat is a limiting factor for outdoor exposure. At altitude in winter, skiers often spend 6–8 hours continuously outdoors without the heat-induced breaks that limit beach time. Extended duration multiplies total UV dose.

• Cloud cover misconception:overcast ski days are not lower UV. Mountain cloud cover scatters UV similarly to valley cloud cover. A flat-light overcast ski day at 10,000 feet may still deliver UV Index equivalent of 8–10 from the sky plus reflected from snow.

Part 6: US High-Altitude Recreation Locations

Location	State	Elevation	Primary UV Risk	Spec
Breckenridge Ski Resort	CO	Base 9,600 ft / Peak 12,840 ft	Extreme — altitude + snow reflection	Cat 3–4 UV400 goggle
Vail Ski Resort	CO	Base 8,120 ft / Back Bowls 11,570 ft	Extreme	Cat 3–4 UV400 goggle
Park City Mountain Resort	UT	Base 6,900 ft / Peak 10,026 ft	Very high–extreme	Cat 3 UV400 goggle
Jackson Hole Mountain Resort	WY	Base 6,311 ft / Peak 10,450 ft	Extreme	Cat 3–4 UV400 goggle
Mammoth Mountain	CA	Base 7,953 ft / Peak 11,053 ft	Extreme	Cat 3–4 UV400 goggle
Mt. Baker Ski Area	WA	Base 3,500 ft / Peak 5,089 ft	High (altitude + frequent snow)	Cat 3 UV400 goggle
Colorado Fourteeners (hiking)	CO	14,000+ ft	Beyond extreme	Cat 4 UV400 close-fit frame or glacier glasses
Rocky Mountain National Park (hiking)	CO	Trailhead 8,000–11,000 ft	Extreme	Cat 3 UV400 with side coverage
Grand Teton National Park (hiking)	WY	Trailheads 6,700–8,000 ft	Very high–extreme	Cat 3 UV400
Glacier National Park (hiking)	MT	Valley trails 3,000–5,000 ft / Alpine 7,000–10,000 ft	High to extreme (upper elevations)	Cat 2–3 UV400 by elevation

Part 7: Lens Category at Altitude

• Category 2 (18–43% VLT):adequate for lower mountain elevations (below 5,000 ft) and for driving mountain roads with frequent tunnel and shade transitions. Too light for sustained high-altitude outdoor activity above 8,000 feet in snow environments.

• Category 3 (8–18% VLT):the standard for mountain hiking above 5,000 feet, ski resort use, and all sustained high-altitude outdoor activity. Provides adequate darkness for direct altitude UV and the initial snow reflection contribution. UV400 is non-negotiable at altitude.

• Category 4 (3–8% VLT):for the most extreme altitude UV environments: Fourteeners in summer, glacier crossings, extended high-altitude snow environments above 12,000 feet, and any situation where snow covers 360 degrees of the visual environment (open snowfields, above-treeline ski terrain on clear days). Not for driving.

Part 8: When Category 4 Is Appropriate

Category 4 lenses transmit only 3–8% of visible light. They are the darkest standard lens category. In most contexts they are too dark for practical use and they are specifically excluded from driving. But in high-altitude snow environments, they match the actual UV exposure conditions:

• Colorado Fourteener summer summits:above 14,000 feet in clear summer conditions, UV is 40–45% above sea level plus any snow or rock reflection. Cat 4 is justified for summit approaches and extended time above treeline.

• Glacier crossings:glaciers on Mt. Rainier, the Cascades, or the Wind River Range in Wyoming present ice and snow reflection that matches or exceeds ski resort conditions. Traditional glacier glasses (dark Cat 3–4 lenses with leather side shields to block lateral reflection from below) are the appropriate format.

•Open above-treeline ski terrain on clear days:high bowls, couloirs, and above-treeline runs at resorts like Arapahoe Basin or Loveland Pass on clear days with fresh snow create conditions that justify Cat 4 within the goggle format.

Cat 4 within a goggle frame is the correct specification for these situations. In goggle format, the driving exclusion is moot (you are not driving on skis). The complete facial coverage of a goggle frame also addresses the reflected UV from below that Cat 4 lenses with standard sunglass frames would still allow to reach the eye from underneath.

✨ NAVI EYEWEAR — UV400 FOR EVERY ALTITUDE.

UV400 polycarbonate. Gray polarized Cat 3 for mountain hiking and driving. Amber for ski flat-light.

At altitude, UV400 is not optional. The thinner the air, the more UV reaches the eye.

Buy 1, Get Any 3 Pairs Free — $119 for four pairs (~$30 each). Free shipping. Free replacements.

Shop:navieyewear.com/collections/polarized

Part 9: Goggle vs Eyeglass Sunglasses for Skiing

For skiing and snowboarding, goggle format is strongly recommended over eyeglass sunglasses for multiple reasons beyond UV:

• Face coverage:goggles cover the entire orbital area, blocking reflected UV from snow that reaches the eye from below, from the sides, and from peripheral angles that eyeglass frames do not protect.

• Anti-fog:ski goggles have ventilation and anti-fog coatings designed for the rapid temperature changes of high-speed downhill skiing. Standard sunglass lenses fog in ski conditions.

• Secure fit:goggles attach around the head with an elastic band and seal to the face, remaining secure during falls, high-speed runs, and physical effort. Sunglass frames can be dislodged.

• Wind protection:at skiing speeds, wind chill and particle impact from snow spray require eye coverage beyond what open-frame sunglasses provide.

• UV protection area:the full wraparound goggle lens eliminates peripheral UV angles that reach under standard sunglass brow frames.

For hiking and non-skiing mountain use, close-fit wraparound sunglass frames with UV400 Cat 3 lenses are appropriate. The key frame requirement at altitude: enough frame coverage to reduce the reflected UV from below and from the sides, without the full goggle seal required for ski conditions.

Part 10: Tint Choice for Mountain Conditions

Gray Polarized UV400 Category 3 — All-Conditions Mountain Standard

Gray polarized Cat 3 is the mountain hiking and variable-condition outdoor pair. Color accuracy for trail navigation, color-coded trail markers, safety equipment signals, and driving mountain highways. Polarization eliminates the horizontal glare from stream crossings, mountain lakes, and wet rock surfaces. Cat 3 for altitude UV levels. The most versatile single mountain outdoor pair.

Amber Polarized UV400 Category 2–3 — Flat-Light Ski and Mountain Overcast

Amber polarized Cat 2–3 for flat-light overcast ski days where terrain definition is the primary visual challenge. Overcast ski days at Breckenridge, Vail, or Park City are characterized by diffuse flat light that eliminates the natural shadow-based terrain cues that define slope features. Amber’s blue-scatter filtering creates artificial depth contrast from the diffuse light, making slope features visible that gray would leave featureless. The most valuable tint for a skier who faces frequent overcast conditions.

Rose / Pink Polarized Category 1–2 — Extreme Flat-Light Ski

For the most extreme flat-light ski condition — complete whiteout overcast where even amber does not provide adequate terrain definition — rose or pink Cat 1–2 provides maximum contrast enhancement with a warm color cast. Rose is the flat-light specialist for ski goggles. Not for bright alpine sun conditions.

Part 11: Driving Mountain Roads

Mountain road driving presents specific lens category constraints different from open ski terrain:

• Frequent tunnel entry (I-70 mountain corridor, US-6, US-40):Colorado’s mountain highway system includes numerous tunnels and rock cut sections that produce rapid light level transitions. Category 3 in a tunnel creates visual under-performance during adaptation. Cat 2 handles mountain highway driving more safely.

• Shade-to-sun transitions:mountain canyon roads alternate between direct sun and deep shade from canyon walls. Cat 2 adapts more comfortably than Cat 3.

•Dawn and dusk mountain driving:low-angle sun at altitude on east-west mountain corridors (I-70 eastbound out of Summit County, US-40 eastbound over Berthoud Pass) combines the low-angle glare of regular dawn/dusk driving with altitude-amplified UV intensity.

Mountain road driving specification:gray polarized UV400 Category 2. Reserve Cat 3 for open mountain outdoor activity, not mountain highway driving.

Part 12: Summer Hiking at Altitude

Summer hiking above 10,000 feet in the Colorado Rockies, the Wind Rivers, the Sierra Nevada, and the Cascades involves the highest UV conditions accessible to recreational hikers without technical equipment:

• Above treeline:no canopy UV protection. Direct overhead UV plus whatever surface reflection exists from exposed rock, snow patches, and alpine lakes.

• Snowfield crossings:summer snowfields on popular hikes (Rocky Mountain National Park, Mt. Elbert approach, Half Dome, Mt. Whitney) provide 50–80% UV reflection from old snow.

• Peak UV timing:above treeline in summer, UV intensity peaks 10am–2pm. Most altitude hiker summit attempts occur during this window. The combination of 10am–2pm timing at 12,000+ feet is the highest UV exposure window available to recreational hikers.

• Specification:UV400 Cat 3 minimum for any above-treeline summer hiking. Cat 4 for extended time above 13,000 feet on clear days or any glacier crossing. Close-fitting frame that covers peripheral and under-eye angles.

Part 13: Year-Round Alpine UV

Mountain UV does not follow the intuitive seasonal pattern that lowland UV does. In spring and fall, mountain UV remains significantly above lowland equivalent values because snow cover extends well into May in Colorado and Wyoming, maintaining the snow reflection multiplier even as lowland UV declines. A late April ski day on Arapahoe Basin (which sometimes stays open through June) involves spring sun angle (UV Index 5–6 at sea level) multiplied by altitude and fresh spring snow reflection to produce total UV exposure comparable to a clear summer day at a lower elevation.

In winter, the low sun angle reduces direct UV significantly — but snow reflection from flat morning and afternoon light at low angles can still be intense for the eyes, particularly for the skin and eye areas directly beneath the brow line that receive reflected upward UV from the snow. UV400 eye protection year-round for any snow-environment mountain recreation is the correct protocol regardless of what the sun angle theoretically predicts for direct UV.

Part 14: Comparison Table — High-Altitude UV Scenarios

Scenario	Elevation	UV Risk	Recommended Spec
Driving I-70 Denver to Vail (variable)	5,280–8,000 ft	High (altitude)	Gray polarized Cat 2 (tunnels + transitions)
Ski resort day, overcast (flat-light)	8,000–12,000 ft	Very high (altitude + snow)	Amber polarized Cat 2–3 goggle
Ski resort day, clear (bright sun)	8,000–12,000 ft	Extreme (altitude + snow)	Gray polarized Cat 3–4 goggle
Above-treeline summer hiking, CO	10,000–14,000 ft	Extreme–beyond scale	Gray or amber UV400 Cat 3 close-fit frame
Colorado Fourteener summit	14,000+ ft	Beyond extreme scale	Cat 4 UV400 close-fit or glacier glasses
Glacier crossing (Mt. Rainier, WY Wind Rivers)	8,000–14,000 ft	Extreme (altitude + ice/snow)	Cat 3–4 UV400 glacier glasses with side shields
Mountain biking below treeline	5,000–8,000 ft	High to very high	Amber or gray UV400 Cat 2–3
Snowshoeing, open terrain	6,000–10,000 ft	Very high (altitude + snow)	Gray or amber UV400 Cat 3
Rocky Mountain National Park trail hiking	8,000–11,000 ft	Very high–extreme	Gray UV400 Cat 3 with coverage frame
Overcast flat-light winter ski, Cascade resorts	3,500–5,000 ft	High (altitude + snow)	Amber polarized Cat 2 goggle

Part 15: Best For

Gray Polarized UV400 Category 3 — Best For:

•Summer mountain hiking above treeline at Colorado, Wyoming, and Utah elevations where direct UV at altitude is the primary exposure

•All-conditions mountain outdoor activity where color accuracy for navigation and safety color coding is needed alongside Cat 3 darkness

Amber Polarized UV400 Category 2–3 (Goggle Format) — Best For:

•Overcast flat-light ski days at Colorado, Utah, and Wyoming ski resorts where terrain definition is lost in uniform diffuse light

•Cascade resort skiing where overcast dominates and flat-light contrast is the primary visual challenge

Category 4 UV400 Close-Fit or Glacier Format — Best For:

•Colorado Fourteener summits and above-treeline approaches in clear summer conditions

•Glacier crossings on Mt. Rainier, the Wind Rivers, and similar environments where ice and snow reflection creates sustained extreme UV from multiple directions

Part 16: Common Mistakes

•Skiing without UV400:the most serious high-altitude UV protection error. A ski day at 10,000 feet without UV400 eye protection delivers extreme UV to the lens and retina. Even fashion-forward ski goggles without UV400 certification are providing no UV protection.

• Assuming cold weather means low UV:cold temperature and UV intensity are independent. A March ski day at Breckenridge is among the highest UV environments accessible to recreational users in the US. Cold does not attenuate UV.

• Using Cat 3 sunglasses for mountain road driving:Cat 3 over-darkens tunnels and shade-sun transitions on mountain highways. Gray polarized Cat 2 is the correct mountain road driving spec.

• Not using goggle format for skiing:standard sunglass frames leave the orbital area partially exposed to reflected UV from below and wind damage at skiing speeds. Goggle format provides the complete coverage that mountain snow environments require.

• Using amber or rose for sunny bright-snow alpine conditions:amber and rose are flat-light specialist tints. On a clear bright day with fresh snow at altitude, gray Cat 3–4 is the correct spec. Amber and rose at Cat 1–2 are insufficiently dark for the luminance of bright fresh alpine snow in direct sun.

Bottom Line

High altitude is the UV environment that consistently surprises people because the conditions that feel least threatening — cold air, overcast sky, winter timing — are the conditions that most thoroughly mislead about UV exposure. Altitude amplifies UV by 30–45% above sea level at typical ski resort and high hiking elevations. Snow reflects 85–95% of that already-amplified UV back upward. The result is UV exposure that can exceed a tropical beach in July, delivered in conditions that feel cold enough to suggest no UV risk.

UV400 Cat 3 for mountain hiking and ski resort use. Cat 4 for Fourteeners and glacier crossings. Goggle format for skiing and snowboarding. Gray for driving mountain roads and clear-day hiking. Amber for flat-light ski days. Year-round because snow extends the high-UV window well into spring and fall at mountain elevations.

Browse UV400 polarized options atnavieyewear.com/collections/polarized. Add 4 pairs — Buy 1, Get Any 3 Free auto-applies. Free shipping. Free replacements.

Frequently Asked Questions

How much does altitude increase UV?

Approximately 3–4% per 1,000 feet of altitude gain, compounding. At 5,280 feet (Denver), UV is approximately 15–20% above sea-level equivalent. At 10,000 feet (typical ski resort mid-mountain in Colorado), UV is approximately 30–35% above sea level. At 14,000 feet (Colorado Fourteeners), approximately 40–45% above sea level. This is before snow reflection is added.

How much does snow increase UV?

Fresh snow reflects 85–95% of UV back upward, adding reflected UV from below to direct UV from above. On a ski slope with fresh snow, total UV exposure (direct + reflected) can be nearly double the direct UV alone. Combined with altitude amplification, this produces some of the highest UV conditions accessible to recreational users.

Do I need Category 4 sunglasses for skiing?

For most ski resort conditions, Category 3 in goggle format is appropriate. Category 4 is warranted for extended time in the most extreme conditions: Fourteener summits, glacier crossings, open above-treeline terrain on clear days with fresh snow. Most recreational skiers are adequately protected by Cat 3 goggle. Cat 4 within a goggle is appropriate for extreme conditions without driving transitions.

Can I wear regular sunglasses skiing instead of goggles?

Not recommended. Ski goggles provide face coverage that blocks reflected UV from snow below and to the sides, anti-fog performance for the temperature changes of skiing, secure fit through falls and high-speed runs, and wind protection at skiing speeds. Standard sunglass frames leave peripheral and lower-orbital areas exposed to the reflected UV from snow surfaces and wind at ski speeds.

What sunglasses do I need for hiking Colorado Fourteeners?

UV400 Category 3 minimum, with Category 4 for extended time above 13,000 feet on clear days or in snowfield crossings. Close-fit wraparound frame geometry to reduce lateral and under-eye reflected UV from snow and rock. If crossing significant snowfields above treeline, traditional glacier glasses (Cat 3–4 with side leather shields) are appropriate for maximum coverage.

Is UV worse in winter or summer at ski resorts?

Summer produces higher direct UV per hour due to the higher sun angle. But total ski-day UV can be high in both winter and summer at altitude because of snow reflection and extended outdoor duration. March and April produce particularly high UV at ski resorts: sun angle is rising (increasing direct UV) while snow cover is still full (maintaining snow reflection). Late-season spring skiing may deliver higher total UV per day than midwinter, counterintuitively.

What tint is best for flat-light ski days?

Amber polarized Cat 2–3 for most flat-light overcast ski conditions. Rose or pink Cat 1–2 for extreme flat-light whiteout conditions where even amber does not provide adequate terrain definition. Gray Cat 3 for clear bright-snow days. The tint switches by sky condition; the lens category is driven by altitude and UV intensity regardless of conditions.

Do I need UV400 sunglasses even on cloudy ski days?

Yes. Overcast ski days at altitude still deliver significant UV through cloud cover (clouds scatter rather than block UV) plus full snow reflection from below. A flat-light overcast day at 10,000 feet on fresh snow delivers UV comparable to a clear summer day at lower elevation. UV400 is non-negotiable for all-day outdoor time at ski resort elevations regardless of sky conditions.

Supporting Articles

•Sunglasses by Climate and Geography: The Complete US Regional Guide

•Sunglasses for Hot, Sunny Climates: The Sun Belt and Southwest Guide

•Sunglasses in the Pacific Northwest: Overcast, Rain and UV

•UV and Eye Disease: The Complete Guide

•Should You Wear Sunglasses on a Cloudy Day? The UV Science

•Sunglasses in Low Light, Night and Variable Conditions: The Complete Guide

•Brown and Amber Sunglass Lenses: Contrast, Depth and Outdoor Performance

•Yellow and Rose Sunglass Lenses: Low-Light Performance Explained

•Navi Eyewear UV400 Polarized Sunglasses Collection

UV400 AT EVERY ALTITUDE. CAT 3 FOR THE MOUNTAIN.

UV400 polycarbonate. Gray polarized Cat 3 for above-treeline hiking. Amber for flat-light ski.

The higher you go, the more UV reaches the eye. UV400 is not optional at altitude.

Buy 1, Get Any 3 Pairs Free — $119 for four pairs. Free shipping. Free replacements.

Shop now:navieyewear.com/collections/polarized

SOURCES & CITATIONS

[1] Sliney DH.“UV radiation ocular exposure dosimetry.”Documenta Ophthalmologica, 1994.View source

[2] Diffey BL.“Sources and measurement of ultraviolet radiation.”Methods, 2002.View source

[3] World Health Organization.“Global solar UV index: a practical guide.”WHO/SDE/OEH/02.2, 2002.View source

[4] Taylor HR, West SK, Rosenthal FS, et al..“Effect of ultraviolet radiation on cataract formation.”New England Journal of Medicine, 1988.View source

[5] Rosenthal FS, Bakalian AE, Lou CQ, Taylor HR.“The effect of sunglasses on ocular exposure to ultraviolet radiation.”American Journal of Public Health, 1988.View source

[6] American Academy of Ophthalmology.“Sunglasses: choosing the right pair for UV protection.”AAO EyeSmart, 2023.View source

High Altitude Sunglasses: UV, Snow and Mountain Conditions (2025)

High Altitude Sunglasses: UV, Snow and Mountain Conditions (2025)