The photochromic lenses automatically change their darkness level to the level of ambient light, but how do they work?
The photochromatic glasses developed in the 1960s, which resulted in intensive research and development work. After some years of work, some smart glasses were created that react to receive the light balance.
Sun glasses vs. photochromatic glasses
The normal sunglasses have glasses that act as a light filter. These glasses are made of materials and components that avoid entrance of the daylight. The polarizing lenses also block the reflected light.
The photochromic lenses work differently. They are made in high quality materials and they use a technology that reacts to ultraviolet rays. This light is not visible to the human eye, but it turns the glasses dark. Inside a building, the phochromatic glasses are translucent because there is virtually no ultraviolet radiation source. In the outer side of a building darkens the phochromatic glasses, because the light of the sun has enough ultraviolet rays.
How do the photochromic lenses work?
The name photochromatic comes from the Greek word: photos and chroma, which mean light and color. The photochromic glasses change color with the light.
By the 1960s, the first photochromic glasses had silver crystals that, when lighted, were transformed into microscopic silver particles. This mechanism works very similar to the negatives of old films.
The current photochromic glasses are made in organic materials. These are the molecules (naphthopyran) that can easily change the molecular structure when they receive ultraviolet radiation. In seconds, the change of these molecules allow the darkening of the glasses.
Crizal Transitions poster Essilor, the world’s leading manufacturer of eyeglass lenses, has created a specific line of photochromic lenses. These are Crizal Transitions: lenses that combine excellent quality with the photochromic treatment.
We offer you different colors: black, gray, brown and green.
The photochromic glasses are an excellent choice for people who wear glasses and sunglasses.