All You Need to Know About Photochromic Lenses

people wearing photochromic lenses
photochromic lenses

Last Updated on July 3, 2024 by Sophia Angel Lou Quiachon

Summer’s here, sun’s out! While we’re all excited for trips over the summer, the increased sunlight also presents challenges to those who wear eyeglasses. Glare from the sun can make it difficult to see clearly, so you may have to constantly switch between eyeglasses and sunglasses when going out.

Fortunately, you have the option to get photochromic lenses to solve your summer frustrations. Photochromic lenses are designed to automatically adjust to changing light conditions so you won’t have to carry and switch between separate glasses. 

Here’s everything you need to know about photochromic lenses.

What are Photochromic Lenses?

Photochromic lenses are designed to adapt to varying light conditions. These specialized lenses are clear when used indoors or in low-light environments, but automatically darken when exposed to ultraviolet (UV) light outdoors.

The primary function of photochromic lenses is to provide clear vision in all lighting situations while offering protection from UV rays. This adaptive quality eliminates the need for users to switch between regular prescription glasses and sunglasses when moving between indoor and outdoor environments.

Are Photochromic and Transitions Lenses the Same?

Photochromic lens is a broad category of light-adaptive eyewear technology. They can be produced by various manufacturers and may be available under different brand names.

On the other hand, Transitions® is a trademark of Transitions Optical, a company that specializes in manufacturing photochromic lenses. Their product line has become so popular that many people use the term “Transitions lenses” to refer to all photochromic lenses, much like how “Kleenex” is often used to describe facial tissues in general.

It’s important to note that while all Transitions® lenses are photochromic, not all photochromic lenses are Transitions brand. 

How Do Photochromic Lenses Work?

Photochromic lenses are designed to adapt to changing light conditions. These lenses contain specialized dyes that respond to ultraviolet (UV) light, causing them to darken when exposed to sunlight and return to a clear state when indoors.

The process begins when UV rays activate the photochromic molecules embedded within the lens material. As these molecules absorb UV light, they undergo a chemical transformation that alters their structure, causing the lens to darken. The intensity of this darkening is directly proportional to the amount of UV light present, which is why the lenses appear darker on bright, sunny days and may maintain a slight tint on overcast days.

Typically, photochromic lenses darken within 30 to 60 seconds of UV exposure. The clearing process is somewhat slower, usually taking 2 to 3 minutes once the UV source is removed. It’s also worth noting that temperature affects this process; colder conditions may result in darker tinting but slower clearing, while warmer temperatures lead to faster transitions but less intense darkening. 

Over time, the responsiveness of photochromic lenses may diminish, but they generally maintain their effectiveness for three years or more.

Types of Photochromic Lenses

Photochromic technology has evolved to accommodate a wide range of vision needs and preferences. These lenses usually come as an ‘add-on’ for various types of lenses from single-vision to progressive lenses.

Plastic Photochromic Lenses vs. Glass Photochromic Lenses

Plastic photochromic lenses are currently the most popular choice for eyeglasses. Compared to glass photochromic lenses, they’re lighter weight, have higher impact resistance, and faster activation and deactivation times. They are also more versatile and compatible with a wider range of lens treatments and coatings.

On the other hand, glass photochromic lenses, while less common, still have their place in the market. These lenses are made from traditional glass with embedded photochromic dyes. Glass lenses excel in optical clarity and offer sharper vision compared to plastic. They are also naturally more scratch-resistant, which can contribute to longer-lasting durability. 

However, glass photochromic lenses are significantly heavier than plastic lenses and are more prone to breakage upon impact. Finally, glass photochromic lenses tend to have a slower reaction time to light changes.

Benefits of Photochromic Lenses

There are a lot of reasons why you should consider getting photochromic lenses. Here are some of its most common benefits:

  • Convenient. With photochromic lenses, you don’t need to carry and switch between separate glasses and sunglasses. This is especially convenient for people who go from bright outdoor environments to lower-light indoor settings frequently.
  • Automatic UV protection. Photochromic lenses block harmful UVA and UVB rays constantly. This provides consistent eye protection throughout the day.
  • Reduced eye strain. By automatically adjusting to light levels, photochromic lenses reduce the need to squint in bright light. This can help prevent eye fatigue and headaches.
  • Adapts to various conditions. Photochromic lenses darken in sunlight and lighten indoors, providing optimal vision in different lighting situations.
  • Compatible with multiple lens material. Photochromic technology can be incorporated into various lens materials, allowing for options like scratch-resistance and impact resistance.
  • Improved low-light vision. Some photochromic lenses can also improve vision in low-light conditions, making them suitable for night driving or situations with dimmer lighting.

Who Should Use Photochromic Lenses?

Young guy wearing eyeglass with photo sensitive lenses, close up shot of his face only

Photochromic lenses are best-suited for athletes and people who are constantly on-the-go. Think runners, outdoor workers, lifeguards, and so on!

These lenses remove the need to carry multiple pairs of glasses or remember to switch between them. Thus, you won’t have to run back inside for your glasses or spend more on a pair of sunglasses—it works as both!

Why Choose Classic Specs?

When it comes to choosing the right photochromic lenses, Classic Specs stands out. The Classic Specs photochromic lenses seamlessly combine style with cutting-edge technology, ensuring you always have the right level of protection and visual clarity, whether you’re indoors or outdoors. 

Moreover, Classic Specs understands that different prescriptions require different lens materials. That’s why we offer photochromic technology in both polycarbonate and 1.67 high-index options. This way, we can ensure that regardless of your prescription strength, you can enjoy the benefits of photochromic lenses without compromising on lens thickness or weight.