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Julbo Explorer 2.0
#2 — Best for Mountaineering & High Altitude

Julbo Explorer 2.0 Review (2026)

Glacier glasses with photochromic lenses that adjust automatically from 6% to 86% light transmission

★★★★☆
9.3/10
Reviewed by William • Updated July 2026 $190

Julbo has built mountaineering and glacier eyewear since 1888, and the Explorer 2.0 is the current version of the company's flagship high-altitude model. The REACTIV lens line is the standout feature: rather than a fixed tint, the lenses actively darken and lighten based on ambient light, moving through a genuinely wide range (as low as 6% to as high as 86% visible light transmission) so the same pair works from a shaded approach trail to full glacier glare without a lens swap.

TrailCraft Score

What Works

  • REACTIV photochromic lenses automatically adjust from category 0 to 4, covering everything from overcast trail to glacier-bright summit conditions in one pair
  • Removable side shields block the intense peripheral glare specific to high-altitude and snow environments
  • 360-degree adjustable temples hold securely under a helmet, over a hat, or bare-headed

Limitations

  • Multiple owner reviews report fogging in humid or high-exertion conditions, since venting is limited by design
  • The frame's wide nose bridge fit runs large for narrower faces

Specifications

LensREACTIV photochromic, 0-4 or 2-4 categories
Weight44g
Side ShieldsRemovable, block peripheral glare
Temples360-degree adjustable
Frame MaterialBio-based Rilsan
WarrantyLifetime

Score Breakdown

Light Adaptability
9.7
Coverage
9.5
Comfort
8.8
Value
8.9

What Sets It Apart

Julbo has built mountaineering and glacier eyewear since 1888, and the Explorer 2.0 is the current version of the company's flagship high-altitude model. The REACTIV lens line is the standout feature: rather than a fixed tint, the lenses actively darken and lighten based on ambient light, moving through a genuinely wide range (as low as 6% to as high as 86% visible light transmission) so the same pair works from a shaded approach trail to full glacier glare without a lens swap.

Removable side shields address a hazard specific to snow and high-altitude environments — intense reflected light entering from the sides — that standard sport sunglasses don't account for, which is why this category is often called "glacier glasses" rather than simply sunglasses.

Glacier glasses with photochromic lenses that adjust automatically from 6% to 86% light transmission

Who This Is For

The Explorer 2.0 is right for: mountaineers and high-altitude trekkers who need one pair of glasses to handle rapidly changing light from tree line to summit, winter hikers dealing with snow glare, and anyone who wants photochromic convenience over swapping tinted lenses.

A note on pricing and links: Prices are current as of July 2026. Some links are affiliate links.

How It Compares

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Common Questions

What does the REACTIV lens category range mean?
Julbo's REACTIV lenses are rated by category (0-4), and the Explorer 2.0's lenses can span this entire range, automatically darkening in bright conditions and lightening in shade or overcast — category 4 is the darkest rating, appropriate for glacier and high-altitude glare.
Do the Explorer 2.0 lenses fog up?
Multiple owner reviews report fogging during high-exertion activity or humid conditions, since the frame's coverage-focused design limits ventilation compared to more open sport-sunglass designs — a tradeoff for the superior peripheral light blocking.
Are the side shields necessary for regular hiking?
For most standard hiking below tree line, they're optional and removable; they become genuinely useful specifically at high altitude, on snow, or on glaciers where reflected light enters from the sides.