Helpful Tips On Photochromic Eyewear

AOSafety SmartLens Shown

AOSafety SmartLens Photochromic Safety Glasses Shown

The majority of customers interested in purchasing Photochromic Eyewear always have the same valid question. How dark can I expect my Photochromic/Transition lenses to get? There is no quick answer to this question. It will depend on the type of glasses you have, and the environmental conditions in which they are used.

How it Works:
Basically photochromic compounds are built into the lens. The sun’s UV rays trigger the compound to darken. When you get away from sunlight, they reverse back to a clear state through a thermal process. This process seems simple enough until you add in environmental conditions, which significantly impact the performance of photochromic eyewear.

When Lenses WILL get their darkest:
  • Cold Weather: Photochromic lenses will get darker in cold weather conditions, which makes them more suitable for snow skiers than beachgoers. (Once inside, away from the triggering UV light, the cold lenses take longer to regain their clear color than warm lenses.)

When Lenses will NOT get their darkest:
  • Driving a car: Most windshields have UV protection built in, which significantly reduces the amount of UV light reaching your lenses. This prevents the photochromic compound from working to its fullest, so lenses will darken considerably less in a car.
  • Hot Weather: The higher the temperature, the less dark photochromic lenses will be. This thermal effect is called “temperature dependency” and prevents these devices from achieving true sunglass darkness in very hot weather.
I want the darkest possible photochromic lenses, what should I look for?
  • Lenses that have a clear neutral state will never get as dark as those that start out darker. If you are seeking darker lenses, try going from a “dark to darker” state. Look for glasses with lenses that are medium or light gray in their neutral state; their transition in the sun will be closer to a sunglass feel than lenses that start as clear.
  • If you’ll be using your eyewear in extremely hot and bright conditions, such as the desert or a tropical beach, photochromic lenses will probably not perform to your satisfaction. I would recommend saving some money and purchase eyewear with traditional dark lens tints.