A group of four friends having a joyful conversation. Two of them are wearing different types of sunglasses.

Prescription Sunglasses vs. Photochromic Lenses: Which Is Better?

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:


What Are Prescription and Photochromic Sunglasses?

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

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.

Photochromic 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.


Prescription Sunglasses: Pros and Cons

What are the benefits and drawbacks of using prescription sunglasses rather than photochromic lenses? Let's take a look:

Pros

  • Less expensive than photochromic lenses: Prescription sunglasses are less pricey than photochromic ones. If you don't need a new prescription, keeping your old glasses and using these shades when needed is the most thrifty option.
  • Better eye protection: This type of lens offers better protection against UV rays. While photochromic lenses take time to transition and may not work as effectively in cars, prescription sunglasses offer more consistent protection.
  • More comfortable: Many people stick with prescription sunglasses because it is what they are comfortable with. Switching between standard glasses and shades also gives you greater control over your vision and your looks. This helps you avoid potentially awkward moments, such as having an unwanted tint in your glasses during photos.
  • Better for driving: These are generally better for driving. While windshields usually provide UV protection, side and back windows typically do not. Wearing prescription sunglasses is the best way to protect your eyes on the road.

Cons

  • May not offer enough protection: You'll need to find a pair of glasses that match your specific needs. Even at their darkest, many types of transition lenses do not block enough light to be comfortable. If you spend much of your day outside, this could be a deal-breaker. Some glasses combine photochromic tech with UV tinting to provide tinted glasses that can get even darker; however, this makes them less versatile for indoor use.
  • Long transition times and residual tint: Some brands and models of glasses contain photochromic dyes that take longer to activate or deactivate than others. Most transition slower in cold temperatures. This can leave wearers blinded by sunlight while waiting for their glasses to darken (particularly when it comes to snow blindness) or feeling awkward while waiting for the tint to disappear while indoors.
  • Most models are not suitable for driving: That UV protection in your windshield is helpful in most circumstances, but it can prevent your transition lenses from activating. If you drive for long periods at a time, you are likely not getting enough UV protection with this type of glasses.

Are Prescription Sunglasses Worth It?

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.


Transition Lenses: Pros and Cons

Are photochromic glasses worth the investment? Let's examine the advantages and disadvantages:

Pros

  • Potentially more cost-effective: These glasses can be pricier than prescription sunglasses. However, as noted above, having one pair of transition glasses can be less costly than buying two pairs. If you need to upgrade your prescription, choosing this type of lens could be the smarter option financially.
  • Convenience: If you go indoors and outdoors many times throughout your day, you may save yourself some time and frustration by switching to photochromic lenses. Instead of juggling glasses, you'll only have to wait a short time for your lenses to activate.
  • Protection wherever you are: While prescription sunglasses offer more consistent protection, you may not always have your shades on hand. Conversely, you never have to worry about forgetting these glasses in the car or back at home. This means you'll always have protection for your eyes from the sun's harmful UV rays.

Cons

  • May not offer enough protection: You'll need to find a pair of glasses that match your specific needs. Even at their darkest, many types of transition lenses do not block enough light to be comfortable. If you spend much of your day outside, this could be a deal-breaker. Some glasses combine photochromic tech with UV tinting to provide tinted glasses that can get even darker; however, this makes them less versatile for indoor use.
  • Long transition times and residual tint: Some brands and models of glasses contain photochromic dyes that take longer to activate or deactivate than others. Most transition slower in cold temperatures. This can leave wearers blinded by sunlight while waiting for their glasses to darken (particularly when it comes to snow blindness) or feeling awkward while waiting for the tint to disappear while indoors.
  • Most models are not suitable for driving: That UV protection in your windshield is helpful in most circumstances, but it can prevent your transition lenses from activating. If you drive for long periods at a time, you are likely not getting enough UV protection with this type of glasses.

Are Transition Lenses Worth It?

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.


Sunglasses vs. Transition Lenses: How to Choose

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.