It is very important to protect your eyes against exposure to UV radiation. But what if you wear glasses and keep misplacing your clip-on sunglasses? Or maybe you can’t find clip-ons that fit your glasses. What if you just don’t like the look of clip-on sunglasses? What do you do then? One option you could consider would be Photochromic lenses.
What are Photochromic Lenses?
The word Photochromic comes from the Greek words ‘photos’ meaning light and ‘chroma’ meaning colour. In layman’s terms, photochromic lenses are lenses that change colour in response to light. However, that isn’t entirely correct; modern Photochromic lenses darken in response to Ultraviolet (UV) radiation rather than light, meaning that they may darken on cloudy days if the UV radiation is high. They will also lighten as soon as you go indoors. Photochromic lenses can also be referred to as transition or reactolight lenses, but use these names with caution as “Transition” and “Reactolight” are also brand names of types of photochromic lens.
Photochromic Lenses vs Polarized Lenses
The most obvious difference between polarized lenses and photochromic lenses are that photochromic lens change their tint based on the amount of UV radiation, whereas polarized lenses are always the same shade of tint. Which type is best will depend on your personal needs. Polarized lenses are perfect if you want permanently dark sunglasses that you put on when you go out and take off when you come in. They are also great if you are ok with the same shade of dark for all occasions. Photochromic lenses are the perfect choice if you don’t want to worry about carrying an extra pair of sunglasses with you and want a lens that darkens to match the UV rays you are experiencing. But there is the catch. Photochromic lenses darken to match UV rays, not light level, so they have their limitations.
What are the down sides of Photochromic Lenses?
Here are a few of the disadvantages of photochromic lenses that you should consider before rushing out to purchase them. They aren’t instant on, instant off; they take a few minutes to adjust to different UV levels. They also adjust to UV rays, not sunlight, so they may, on occasion get darker on cloudy days than they do on sunny days. Because they darken according to UV rays, they are unlikely to work when you are driving, because most car windshields have built in UV protection.
The advantages of Photochromic Lenses
On the other side of the coin, photochromic lenses provide a large number of advantages, not the least of which, you will always have UV protection every time you go outside, as long as you remember to put on your glasses. They are available in various shades of tints and for any type of glasses, including bifocals and progressives. They are money savers, as you don’t have to buy separate sunglasses. They are the best form of eye protection as they absorb 100% of UV radiation.
Not sure if Photochromic Lenses are for you?
Still undecided? When in doubt, the best person to talk to is your optometrist. Your optometrist knows your vision history and will be able to advise you about whether or not photochromic lenses would be a good choice for your vision and your lifestyle. Always get professional advice and don’t take chances with your eyes. You want them to serve you for life.