Photochromic lenses

Have you ever wondered how Transitions® lenses work? The magical mash-up of sunglasses and eyeglasses, when you see them change color, you feel like – the future is now. Transitions® are an example of photochromic lenses.

Some other names for photochromic lenses are Light Adaptive, Variable Tint, Photochromatic, but many people call just them by the popular name brand Transitions®; you could say they’re the the “Kleenex” of photochromic lenses.

If we start with the etymology of the word, photochromic comes from two Greek words; photo meaning light and chroma meaning color.

Photochromic lenses change color when exposed to light.

You can get clear photochromic eyeglasses that change all the way to dark sunglasses, or photochromic sunglasses which are just for outdoor wear (and do not get completely clear.)

So how do Transitions® lenses work? When exposed to light, the photochromic molecules in the lenses begin to change structure, like in the illustration below. This new arrangement allows the molecules to absorb more light which causes the lenses to darken. Most photochromic lenses to UV light; that’s why they change when you’re in the sun yet remain clear indoors.

how do photochromic lenses work

Temperature also has effect on the reaction time of the molecules in photochromic lenses. On a cold day, your lenses will react more slowly than on a warm day.

In this video, one of FramesDirect.com’s expert opticians, Travis, explains further:

 

Transitions® lenses continuously adapt to changing light conditions and block 100% percent of harmful UVA and UVB rays. Having your lenses give you the exact amount of protection you need to see clearly, means your eyes are doing less work. And there’s the added benefit of only having one pair of glasses for indoors and out!

Learn more about Transitions lenses

high index lenses

#FDAnswers: I have a strong prescription. What lenses do I need?

Full disclosure, this post is personal. I have terrible vision. I started wearing glasses when I was about 8 years old. By the time I was 11, I was begging my Mom for contact lenses. This was in the 80’s when high school girls and secretaries in movies would take their glasses off and suddenly be transformed from invisible to gorgeous. Glasses were not pretty – that’s the message I received loud and clear. Thus began a lifelong struggle with glasses, I would only wear them at home, if at all, never in public, and half the time I fell asleep with my contact lenses on. Even as the decades passed and glasses became the fashion accessory du jour, I couldn’t enjoy them. Why? Because my vision is so bad my lenses looked like the proverbial coke bottles, and turned my eyes into blinking little beads.

So that brings us to today. My prescription is -8 in my right eye and -11 in my left. I can’t see ANYTHING without glasses or contacts, but I have found a way to wear my glasses without feeling completely self conscious – three words: High Index Lenses. If your prescription is crazy high like mine, you should get the thinnest possible lens, which is the High Index 1.74. Anything +/- 6 you definitively need them. Another trick I’ve learned is to ask for no edge polish. When your lenses are VERY thick, polished edges call even more attention to them.

Here’s one of our expert opticians, Amanda, talking about the benefits of High Index 1.74 lenses.

 

If your prescription is between +/- 2 and 6, you could get the High Index 1.67 lenses. The 1.74 are the thinnest, but they aren’t available with tinting or progressives, so you may need the 1.67 if you’re looking for those add-ons. The other varieties of lenses – plastic and polycarbonate – aren’t great if you have a prescription that’s +/- 3. High Index lenses are a bit more expensive but well worth avoiding the coke bottle look!

All our high index lenses come with scratch resistant and UV coatings for no additional cost. You can learn more about all the lens types we offer at FramesDirect.com here.

Also see How Do Glasses Work?

#FDAnswers “What does polarized mean?”

Polarized sunglasses are desirable (and slightly more expensive,) because most people know they can greatly improve your vision in bright sunlight. Polarization, when referring to optics, is more than a buzzword or a marketing term. There is science behind why your eyes feel more comfortable, and you see more clearly, when wearing polarized sunglasses. But what does polarized mean?