From long days at the beach during warmer months to the harsh glare from the snow during the winter, protecting your eyes is a year-round concern. Indeed, ultraviolet (UV) rays from the sun can cause serious damage to your vision. When your eyes are exposed to excess UV rays, you can experience vision problems like corneal sunburn, macular degeneration, cataracts, and more.
One of the most effective and common ways to block these rays from affecting your eyes is wearing sunglasses when you are outdoors. Even after you've decided to invest in a pair of shades, however, there is an important decision to make: should you buy prescription sunglasses or photochromic lenses?
Both types have certain benefits, but they have differences that make them suited to different lifestyles as well. Understanding the pros and cons of each is vital before making a purchase. This guide will help you understand the key differences between the two types of lenses:
Before diving into the pros and cons of each, it's important to understand what the terms "prescription sunglasses" and "photochromic sunglasses" refer to.
Prescription sunglasses, much like standard prescription glasses, are designed to refract light to properly focus it on your retinas, improving the sharpness of your vision. Sunglasses have polarized lenses, which provide clearer vision in bright conditions, increase contrast, reduce glare, and minimize eye strain. Further, modern prescription sunglasses have UV protection embedded in the lenses. This allows you to see clearly while still protecting your eyes from the bright, damaging rays of the sun
Note that not every pair of shades is created equally; cheap pairs may not provide sufficient UV protection. As noted by the University of Utah, "Look for a label that says '100% protection against both UVA and UVB' or '100% protection against UV 400.'" Fortunately, prescription sunglasses typically have better UV protection than stock sunglass lenses.
Instead of carrying two pairs of glasses with you wherever you go, you can buy glasses with lenses that contain special photochromic dyes that darken when exposed to UV rays from the sun. These are called photochromic lenses, also called transition lenses. Simply stepping outside will cause this eyewear to darken, a transition which takes around 30 seconds to a minute. Stepping back indoors will cause this process to reverse.
While the exact technology involved has evolved over the years, these lenses have made a serious impact on the eyewear industry for the past few decades. One of the biggest brands offering photochromic lenses is Transitions®, with one of the most popular models being the Transitions® Signature 7 Brown™. These are completely clear while indoors and darken to an 80% tint while outdoors. Note that other lenses tint ratios may vary, with some having some residual tint indoors or darkening to a different degree while outside.
What are the benefits and drawbacks of using prescription sunglasses rather than photochromic lenses? Let's take a look:
Prescription sunglasses may be a smart choice for you. If you frequently drive and need sunglasses to protect your sight, prescription sunglasses may be better than transition lenses for you. You may also prefer these if the idea of a specialized transition coating simply doesn't appeal to you. Just remember that you'll need to bring your shades with you in order to have consistent access to UV protection for your eyes.
Are photochromic glasses worth the investment? Let's examine the advantages and disadvantages:
If you want a single pair of glasses that are reliable in many different situations and offer continuous protection, photochromic lenses will be a good investment. If you spend a long part of each day outdoors, you'll want to make sure you get a pair that are sufficiently tinted. If you drive often, though, you may want a pair of backup prescription shades for the road.
Which type of glasses are best for you will depend largely on your specific needs. When you're buying glasses online, your choice should boil down to what you need and what you personally prefer. If you have a history of losing important items, transition lenses might be better. If you regularly drive for long periods of time, prescription sunglasses may be the superior choice. Whichever you choose, be sure to do your research before shopping to ensure you get the right type for you.