Gauging the Weather: How Extreme Temperatures Affect Light-reactive Lenses

Weather is changing, leaves are falling, and many are gearing up in preparation for the season ahead. Wardrobes have shifted to boots and scarves, and chains are being put on tires for icy roads. Good thing SunSync^® Light-Reactive Lenses provide comfort and UV protection year-round.

Fun fact: Photochromic lenses like SunSync Elite behave differently in cold weather, getting and staying darker longer, especially when you need it on crisp, bright days. Here's how you can educate your patients and ensure they know what to expect.

Did you know? Any SunSync photochromic lens can be paired with Unity^® V3 Elite progressive lenses, helping your presbyopic patients do what they love, better—in any light conditions.

The Science Behind Photochromics

Inside every photochromic lens, ultraviolet-sensitive molecules open and close, almost like microscopic umbrellas, releasing dyes depending on light conditions. This is the science behind the lenses that makes them shift from light to dark.

If you think back to high school science class, you’ll remember that warm molecules move quickly and cooler molecules slow down. Here’s what this means for photochromics:

• In colder temps, lenses take longer to fade back to clear but stay darker longer.
• In hot weather, these light-sensitive molecules move faster, so lenses activate quickly but don’t get quite as dark.

Translating Technology into Patient Benefits

While patients may not love the slightly longer fade-back speed in cold weather, there’s an upside. Cold temperatures allow photochromic molecules to get darker, which is great for bright, snowy days.

Wearing sunglasses in summertime is a no-brainer for most patients, but UV protection is equally important in winter. The sun’s angle can be more intense when it’s lower in the sky, and bright rays bouncing off the snow (a phenomenon called “albedo”) can be downright overwhelming without the right eye protection. In all these conditions, SunSync provides 100% UV protection and a dark, comfortable tint.

It’s a small detail, but one worth sharing with patients—especially in places like the Midwest, or northern climates—so they know what to expect. Because industry tests happen in controlled lab settings, patients might notice that real-world conditions can feel different.

Why SunSync Makes a Difference

SunSync Elite and SunSync Drive XT are built to perform in any season. SunSync Elite fades back faster than the competition², gets darker outdoors, and stays extra clear indoors. It also helps reduce blue light and blocks 100% of UV rays.

SunSync Drive XT is one of the few lenses that holds onto its tint behind the wheel. It changes color quickly while offering 100% UV protection and “always on” blue light filtering, making it a great choice for drivers regardless of season.

Want to show patients how well these lenses work in real life? Ask for a free demo. Both SunSync Elite and SunSync Drive XT come with a one-year satisfaction guarantee for VSP^® patients.

Working with presbyopic patients? Pair SunSync Elite with Unity V3 Elite Progressive Lenses and TechShield^® Elite Anti-Reflective Coatings for all-in-one eyewear that helps your patients do what they love, better, this winter and beyond.

Request a demo today.

<sub>1. t½F of SunSync Elite in polycarbonate is 51 seconds at 73.4°.
2. In independent testing, SunSync Elite fades back to 1/2 T in 53 seconds (59.1% light transmission) vs. Transitions GEN S: ½ T in 75 seconds (53.7% light transmission).</sub>