Your life and eyes 3 min read

How do Photochromic lenses work?

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There are a number of different types of lenses you can wear to correct and enhance your vision; it can be difficult to know which is the right lens type to suit your individual needs! Whether you have a refractive error that needs correcting, or you’re looking for additional protection for the health of your eyes, there’s a pair of lenses to accommodate your need.

Photochromic lenses can offer an advanced solution for those with a busy, on-the-go schedule. If visual comfort is at the top of your list, you might want to consider investing in a pair of photochromic lenses.

If you often experience changing light conditions, such as going from inside to outdoors or vice versa, photochromic lenses could be a helpful lens solution for added convenience.

What are photochromic lenses?

Sometimes known as light adaptive lenses, photochromic lenses will automatically adapt to the changing light conditions around you. This works when the lenses are exposed to UV light and the molecules embedded in the lens change their structure. This change of structure darkens the lenses automatically to provide a comfortable tint, for optimal vision. The colour of tint totally depends on what style you’re trying to match your frame, look or outfit. Each colour provides it’s own colour perception benefit so when selecting which colour it’s important to consider whether you want enhanced contrast, neutral colours or enhanced colours. Your optician will be able to discuss and talk you through this.

The molecules in the lenses are not visible to the wearer or others and when the UV exposure decreases, the lenses will return to a clear state. The most popular brand of photochromic lenses is Transitions(1). They are light intelligent lenses designed to protect your vision from harmful UV light and combat glare, resulting in comfortable vision.

Female looking at laptop screen

Photochromic lenses will work even on a cloudy day because UV rays are able to penetrate the clouds, so your eyes are still protected. Some more advanced technologies, such as Transitions XTRActive, will work even behind a car windscreen by adapting off of visible light too.

The lenses will react instantly upon exposure, constantly working in reaction to the light condition around you. Some photochromic lenses will not react as well with warm temperatures as higher temperatures will try to fade back the lenses to a clear state. This isn’t ideal when you’re exposed to UV light on a hot sunny day. Transitions lenses have been adapted to continue to work even in high temperatures so you know your lenses will reach optimum tint even on a hot, sunny day.

Why would you need to wear photochromic lenses?

Photochromic lenses can offer a high level of protection from UV light, which in turn means your eyes are protected from the risk of eye disease or damage. The adaptive technology means that the lenses will do the work for you, so you can rest assured you are wearing the right protection from the sun at all times.

This is highly important for your eye health. Over-exposure to UV light has been linked to an increased risk of cataracts(2). The technology in photochromic lenses will block 100% of UVA and UVB light rays.

Woman riding a bike wearing Transitions

If you spend a lot of time going from indoors to outside, whether it’s for leisure or work, photochromic lenses can provide convenience. What’s more, you can combine your photochromic lenses with your corrective lens requirement, so you’re able to experience natural vision when it’s needed most.

Photochromic lenses are often recommended for playing sport or if you are particularly sensitive to light, as the lens design can provide optimal comfort in all light conditions.

So, if it’s time for you to invest in a new pair of lenses for everyday wear, photochromic lenses could be the perfect solution.



(1) Transitions lenses are the brand of photochromic lenses most often recommended by eyecare professionals. Transitions Eyecare Professional Brand Tracking (MSW-ARS, 2016: Brazil, Canada, Colombia, France, Germany, Italy, Mexico, Spain, United Kingdom, and United States)

(2) McCarty CA, Taylor HR. A review of the epidemiologic evidence linking ultraviolet radiation and cataracts.

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