Photochromic lenses have been a major breakthrough for both sunglasses and prescription glasses, because they can adapt to the light outdoors and darken in a matter of seconds. But… what do we mean when we say they adapt so quickly? Quite simply, photochromic lenses are able to darken or lighten depending on the amount of sunlight they receive. Here we explain how it works!
What are photochromic lenses?
Photochromic lenses are lenses treated with copper or silver chloride, a compound that reacts to the UV rays emitted by the sun. This makes the lens of the glasses darken or lighten depending on how much sunlight is hitting it at any given moment.
That is why it is important to remember that they only work with the natural UV rays emitted by the sun. In other words, photochromic lenses will only darken outdoors in natural daylight; if you expose them to artificial light, they will stay clear.
Pros and cons of photochromic lenses
Starting with the advantages, the first thing to say is that they are a two-in-one: you get your sunglasses and your prescription glasses in a single pair. Why? Very simple: they can be made to your prescription to correct all kinds of vision problems. Another advantage is that they are extremely useful for outdoor sports, where the light can change drastically in a very short time. The lens adapts quickly to prevent the discomfort that sunlight can cause.
But we also need to talk about the drawbacks. The main one is the time they take to darken. When they were first launched and people started wearing them, they were rather slow, but the technology keeps improving and today’s photochromic lenses are much faster.
Finally, there is the drawback when it comes to driving. Nowadays almost every vehicle has a windscreen with UV protection, so the lenses will not darken inside the car because the UV light never reaches them. On top of that, you need to be careful with glare, because this type of lens does not do the same job as polarised lenses, which neutralise horizontal reflections.
Who are photochromic lenses for?
Photochromic lenses can really be worn by anyone, except in the situations we have just mentioned. You should also bear in mind the problem caused by horizontal reflections (glare), which can only be eliminated with a polarised lens.
Can they be adapted to any vision problem?
Yes, photochromic lenses can be made to your prescription to correct your vision problems.
Photochromic lens options
At Lens4Glasses we currently offer two main photochromic lenses:
ZEISS
ZEISS PhotoFusion lenses (single vision) are available in high and medium indices and feature the latest advances in light-sensitive technology. They darken and clear quickly, so they offer excellent visual comfort.
ESSILOR
Essilor Transitions lenses give you comfort and safety against UV light in any setting, as there are more elegant versions and others that are ideal for the car, as well as a wide range of colours.
Now you know what photochromic lenses are (lenses that darken in the sun), together with their advantages and possible drawbacks. It is important to keep these points in mind when choosing the most suitable type of lens for your sunglasses or prescription glasses. Above all, in this case, consider whether you often spend time or drive in places with a lot of horizontal glare. At Lens4Glasses we will be delighted to advise you and help you choose the lenses that suit you best.
Don’t hesitate to get in touch with us if you have any questions.