Photochromic crystals: What are they and how do they work?

In addition to the well-known polarized lenses to protect your eyes from solar radiation, there are also so-called photochromic lenses.

Do you know them?

A curiosity of photochromic crystals

In the 1960s an American chemist, Stanley Donald Stookey, discovered the reversible chemical reaction of some crystal molecules, but it was not until the 1990s that they began to be commercialized.

Today, thanks to technological advances in this regard, photochromic treatment can be applied to all types of prescriptions, and is available for both our single vision and progressive glasses.

How do photochromic lenses work?

They are photochromic lenses, which means you will see them differently indoors than outdoors.

Indoors or at night, these photochromic lenses work just like regular prescription lenses. It they lighten until they once again have the transparency of a normal graduated glass.

Outdoors, when exposed to ultraviolet radiation from the sun, they darken automatically like sunglasses and thus help reduce glare, quickly improve the quality of vision and contrast.

This darkening of the glass is due to a treatment that we apply to the lenses and which produces this photochemical reaction that blocks 100% of the harmful ultraviolet radiation.

When is it recommended to wear photochromic glasses?

• if you suffer from eye sensitivity
• if you work many hours a day outdoors
• if you change a lot from indoor to outdoor environments

• Respond quickly to light variations
• Gain sharpness of the image and better definition of contrasts
• Protect your eyes against UVA rays without having to change your glasses

When are they not recommended?

The only contraindication is that it is not recommended to use them while driving, because the car's windshield absorbs UV radiation, which prevents the lens from working properly.

Although technology is advancing rapidly to address these cases, we still recommend the use of traditional sunglasses, especially for long distances.

Would you like to switch to light-adaptive lenses ?

You can choose any frame from our collection and select the option of "Glasses Photochromic".

If you have any questions, we will assist you via chat or via email to hola@greyhounders.com.
We are waiting for you!