Common Diving Mask Tints and VLT Values

• Mirror-coated lenses: Lower VLT (≈10–25%), reducing glare at the surface.
• Tinted ‘color correcting’ lenses: Usually 25–40% VLT, balancing contrast/color and sufficient light for viewing.
• Clear: 80%+ VLT, not color correcting but best for darkness or training.

• Description: These lenses automatically darken in sunlight and become nearly clear in low light. They adjust according to ambient UV/light levels, which can help divers adapt to varying conditions between surface and depth.
• VLT Range: Typically, photochromic lenses span a wide VLT range (for example, 10–80% VLT), depending on exposure—darker at the surface or in sun, clearer as you descend and the UV fades.
• Color: Often available in brown or gray base; some specialty photochromic dive lenses are being developed for color correction.
• Benefits:
• Surface: Acts like sunglasses (darker, lower VLT).
• At depth: Fades clear for maximum light (higher VLT), aiding underwater visibility.
• Versatility: Reduces need for separate surface and depth masks.

• Use in Diving: Polarized lenses are less common under water (more for surface sports like fishing); their main benefit is significant glare reduction at the surface, but underwater their effect is limited.
• VLT: Depends on base tint and polarization; most polarized sunglasses for surface wear have a VLT between 10–20% but are not usually advised for underwater diving.

• Deep, Blue Water (>10 meters): Red-tinted mask, 25–40% VLT—for restoring natural color.
• Green, Murky Water: Magenta-tinted mask, 25–40% VLT—counteracts color loss in algae-rich or turbid water.
• Low Light/Night Diving: Yellow/amber lens, 60–80% VLT—for enhanced contrast and brightness.
• Bright, Shallow, Surface Work: Mirror/tinted lens, 10–25% VLT—glare reduction, eye comfort.
• All-Purpose/Changing Conditions: Photochromic (transition/polychromic) mask—VLT 10–80%—for versatility from surface sunlight to depth shadow.

Note: Adding any tint reduces total light transmission somewhat. Photochromic/transition lenses offer maximal flexibility for divers frequently transitioning between sunlit surface and deeper water, but are newer to the dive industry and may have limited color-correcting options compared to dedicated red/magenta/yellow tints.

• Choose tint and VLT to match your most frequent dive conditions.
• Transition/photochromic dive mask lenses are emerging and provide great adaptability but check for color-correcting options if underwater color fidelity is critical.
• For specific VLTs, aim for ~25–40% for color correction, 60–80% for low light, and 10–25% for surface glare.

• For deep sea and tropical diving below 10 meters, a red-tinted mask enhances color correction.
• For green/temperate waters, magenta is preferred.
• For low-light or murky conditions, yellow or amber tints help.
• Clear lenses remain versatile but don't enhance color at depth.