Julbo Lenses: Understanding Each Technology (REACTIV, Alti Arc, Spectron)

Julbo designs lenses crafted for adventure. On Visionet, we offer the full range: you can filter by lens type (REACTIV, Alti Arc, Spectron, polarized…) to quickly find the model suited to your activity. We are among the best Julbo sellers in France – wide choice, availability, and clear advice.

View all Julbo sunglasses

Tip: If you are looking for a specific Julbo lens, use the filter by lens type.

1REACTIV Lenses (photochromic)

REACTIV lenses automatically darken and lighten according to the light. Ideal when the weather changes, or when moving from shade to full sun without stopping.

REACTIV 0-4 High Contrast

Ultra-wide range (UV0→UV4): from 100% translucent to very dark. Grey base with variable red mirror; increased terrain reading and effective anti-fog for intense efforts. A single lens for night, dawn, and glacier. Ideal for early starts, transitions between forest/clearings, or alpine routes where the weather changes quickly. The tint change is progressive and fast, avoiding the need to remove glasses in tunnels or undergrowth, while offering excellent protection at the summit.

VLT ≈ 86% → 4%* | Cat. 0 to 4 | Anti-fog & oleophobic. Excellent helmet/mask compatibility.

PhotochromicHigh Contrast

REACTIV 2-4

Designed for the mountains: cat. 2→4 transition, brown base to highlight terrain and choice of flash mirrors. Clear vision in full sun as well as under cloudy skies, without changing glasses. Fast transition for valley approaches, snowfields, and exposed ridges; perfect for summer mountaineering, high-route trekking, and high-altitude gravel biking.

VLT ≈ 35% → 7%* | Anti-fog + oleophobic. Durable comfort on long days, simplified maintenance.

MountainPhotochromic

REACTIV 2-4 Polarized

The high mountain reference: photochromic 2→4 + polarization (≈99%) to cut glare on snow and water. Enhanced contrasts, relaxed vision on long outings. Ideal for ski touring, glacier expeditions, and offshore sailing where glare is constant. Anti-fog/oleophobic treatments keep lenses clean despite wind, powder, and perspiration.

VLT ≈ 20% → 5%* | Anti-fog + oleophobic | Brown base, dark mirror. Chromatic stability without color distortion.

PolarizationHigh Altitude

REACTIV 2-3 Glare Control

Photochromic & lightly polarizing (~85%) lens: reduces reflections while remaining compatible with screens. Trivex material: very light, sharp optics, high resistance. Excellent "all-terrain" option for running, mountain biking, coastal sailing, and daytime driving where GPS, watches, and meters are frequently consulted.

Cat. 2 to 3 | Variable VLT* | Ideal for sport & daily use. Trivex: clarity close to mineral, featherlight.

Glare ControlTrivex

REACTIV 1-3 Light Amplifier

Designed to boost brightness when it's lacking, while increasing to cat. 3 when the sun returns. More legible details, more vivid colors. Perfect for dense forests, changing weather, urban sports at dawn/dusk, and low winter days.

VLT ≈ 75% → 17%* | Anti-fog + oleophobic. Reduces eye strain in low light.

Versatile

REACTIV 0-3 High Contrast

From night to full day (cat. 0→3). Grey base + discreet red mirror; accentuated contrast and anti-fog treatment to keep the view clear in all circumstances. Ideal for very early morning outings, urban running with tunnels and shaded areas, or bike commutes.

VLT ≈ 87% → 15%*. Smooth transition, no "on/off effect".

0→3

REACTIV 1-3 Glare Control

Photochromic 1→3 with moderate polarization (~56%): cuts glare without hindering screen reading (GPS, meter). Finishes: copper base + rose mirror or grey base + silver mirror. Excellent choice for city, road, and freshwater sports where instrument reading and light variations alternate.

VLT ≈ 46% → 10%* | Oleophobic. Natural vision, minimal distortion.

Screen Compatible

2Alti Arc 4 Mineral Lenses

Alti Arc 4

The choice for high altitudes. Very dark mineral cat. 4 lens, often with a brown base to improve terrain reading. Excellent scratch resistance, anti-reflective and hydrophobic treatments to maintain clear vision even with wind, snow, and splashes.

Category 4 | Maximum protection (not recommended for driving) | Ideal for glaciers and strong glare.

MineralGlacier

3SPECTRON & SPECTRON HD Lenses

Polycarbonate lenses: lightweight, shock-resistant, and available in polarized versions as needed.

Spectron HD 4 Polarized

Cat. 4 polarized (~80%) to cut glare on water and snow. Dark tint (low VLT) with blue mirror depending on model and hydrophobic treatment.

Category 4 | VLT ≈ 7%* | Sea & high light.

Polarized

Spectron HD 3 Polarized

Clear and contrasted vision for everyday use: ~80% polarization compatible with screens, hydrophobic treatment, and mirror depending on versions. UV protection cat. 3.

Moderate VLT* | Unbreakable polycarbonate.

Daily UsePolarized

Spectron HD 3

Fixed cat. 3 tint for strong light, enhanced color rendering and contrast specific to the HD series. Hydrophobic to repel water.

VLT ≈ 15%* | Ideal for cycling, sunny city.

Spectron 3 Polarized

Polarizing to eliminate glare (water, snow, asphalt) with cat. 3 protection. A good multi-purpose companion.

VLT ≈ 12%*.

Polarized

Spectron 3

Cat. 3 polycarbonate, lightweight and resistant. Available with mirror finishes for style and anti-glare.

VLT ≈ 13%* | Sport & urban use.

Polycarbonate

Spectron HD 1

Soft tint for low to variable light (end of day, changing weather). High visual comfort and impact-resistant materials.

Category 1 | VLT ≈ 45%*.

Low Light

Spectron 4

Cat. 4 protection for extreme light (high mountains, very bright beach). Very dark; not recommended for driving.

Very low VLT* | Lightweight & resistant.

Cat. 4

Polar Junior

Polarized version for children: reduces glare and improves visual comfort during outdoor activities. Designed to withstand daily use.

Polarizing | Designed for young users.

Children

4FAQ – Julbo Lenses

REACTIV, Spectron or Alti Arc: what are the differences?

REACTIV: photochromic, they automatically adapt their tint (ideal when light varies). Spectron: fixed polycarbonate (with or without polarization), lightweight and robust for sport and daily use. Alti Arc: very dark cat. 4 mineral lens for extreme sun and strong glare (glacier).

Which lens for high mountains/glaciers?

Alti Arc 4 or REACTIV 2-4 Polarized: maximum protection and glare management on snow. Spectron 4 also suitable, but without the adaptability of REACTIV.

Category 4 and driving: is it allowed?

No, category 4 lenses (very dark) are not recommended for driving as they significantly reduce light transmission. Opt for cat. 2–3 (or REACTIV which lighten).

Polarization: compatible with screens?

Strong polarization can darken or cause some screens to shimmer. Choose REACTIV 2-3 Glare Control (~85%) or REACTIV 1-3 Glare Control (~56%) to maintain good readability of GPS/meters.

REACTIV lens change speed?

The transition occurs in a few seconds and continuously adjusts according to UV and temperature. The advantage: you keep your glasses on permanently, from undergrowth to full sun.

How to choose on Visionet?

Use our filters by lens type (REACTIV 2-4, Alti Arc, Spectron 3 Polarized, etc.). You can also sort by activity (trail, mountain biking, mountaineering, sailing) and by color/mirror. Need help? Contact us, we'll guide you according to your use.

* Luminous transmission values (VLT) are given as an indication according to manufacturer documentation and may vary slightly depending on color and mirror treatment.