Lifestyle + Fashion

Self-tinting lenses for more comfortable vision, flexibility and protection

Tips from BETTER VISION: who should wear photochromic prescription lenses by ZEISS and when?

16 September 2022
  • Self-tinting lenses for more comfortable vision, flexibility and protection

Modern self-tinting lenses, like  ZEISS PhotoFusion X  can be a reliable and convenient solution for the changing light conditions in your life. PhotoFusion X lenses are there for you all day, both indoors and outdoors, making your life more comfortable in changing light conditions. They are available in various stylish colors and provide full protection against harmful UV rays. Let us show you who can benefit most from photochromic prescription lenses and in which situations.

A small but significant invention by chemist Stanley Donald Stookey and his colleague William Armistead in the 1960s made it possible to manufacture prescription eyeglass lenses that react to UV rays. Now, high-performance self-tinting lenses are available, such as ZEISS PhotoFusion X, which can become as dark as sunglasses very quickly and appear totally clear to the wearer indoors.  

A cloudy day with no obvious sunshine: PhotoFusion® X Lenses by ZEISS still protects the eyes against harmful solar UV radiation.

A cloudy day with no obvious sunshine: PhotoFusion® X Lenses by ZEISS still protects the eyes against harmful solar UV radiation.

When outside, PhotoFusion® X Lenses darken according to the sunlight giving 100% solar UV protection.

When outside, PhotoFusion® X Lenses darken according to the sunlight giving 100% solar UV protection.

Even if the sun is shining outside, PhotoFusion® X is very clear in closed rooms and offers best vision.

Even if the sun is shining outside, PhotoFusion® X is very clear in closed rooms and offers best vision.

We have put together some tips to give you an idea of which wearers and situations are an ideal fit for self-tinting lenses:

  • PhotoFusion X prescription spectacle lenses with a high or medium refractive index darken in just 15 to 30 seconds in bright light or sunlight

    Do you need your glasses all the time? Does it bother you always having to carry two pairs of glasses wherever you go so you can see perfectly indoors and protect your eyes against glare and UV rays when it's sunny outdoors? Glasses with self-tinting lenses can make your life more comfortable, as you always have the right tint for all light conditions in one pair of glasses. PhotoFusion X prescription eyeglass lenses with a high or medium refractive index darken in just 15 to 30  seconds in bright light or sunlight.1 Indoors, they brighten again in as little as 2 minutes1, becoming clear enough to see distinctly in a short time. Of course, they also offer full protection against solar UV rays at all tint levels.

  • Are you particularly sensitive to light? Maybe you simply have to reach for your sunglasses faster than others. Even though the sun is barely peeping out from behind the clouds, you already find seeing strenuous. Self-tinting lenses can be a wonderful vision aid to reduce the discomfort for your eyes, as they adapt to the respective light conditions almost without limit. In weak sunlight they darken less, so you can still see well despite the darkening effect.

  • All day solution: Self-tinting lenses for all day changing light conditions

    You  are used to having two pairs of glasses – one clear lens solution for indoors and another lens solution for the sun outdoors, and you're fed up with changing glasses all the time. For you, self-tinting lenses are the right all day solution and not a luxury. They can be an important tool when it comes to making your daily life easier and feeling more comfortable. Your glasses quickly change from normal ones to sunglasses as soon as you walk from indoors to outdoors – and vice versa. You have the right lens solution for every type of light condition, whether you’re spending time indoors or outdoors, on sunny or cloudy days.

  • Are you active or sporty? The weather doesn't always cooperate, or the light conditions change frequently during sporting activities. You have no time to change your glasses. Self-tinting lenses mean that you are ideally equipped for any light conditions that occur right from the start. Your PhotoFusion® X prescription eyeglass lenses change their tint from clear to dark and dark to clear quickly. At the same time, they protect your eyes against the harmful UV radiation and reduce glare on sunny days.

  • One pair of glasses for every situation: just as  progressive lenses  can save you the trouble of constantly having to switch your reading glasses for your regular glasses, self-tinting lenses can save you from constantly having to switch between sunglasses and normal glasses. Losing, forgetting or not knowing where to put your second pair of glasses – they’re a thing of the past now. Enjoy each moment – thanks to optimal vision in all light conditions.

  • Your contact lenses – whether daily, monthly, annual or multifocal lenses – are your go-to solution. But there are situations where you need glasses. At the same time, you still want to be as free and active as before, e.g. during sporting activities. Sports eyeglasses with curved and self-tinting lenses can become your best training partners.  Whether indoors or outdoors, on sunny or cloudy days, you always have the right tint and UV protection while experiencing less glare. You only need one vision aid for relaxed vision.

  • ZEISS PhotoFusion X, are available in natural, modern colours - just like normal sun lenses

    The days when self-tinting lenses looked old-fashioned and frumpy are long gone. Modern self-tinting lenses, like ZEISS PhotoFusion X, are available in natural, modern colors – just like normal sunglass lenses. Self-tinting lenses can also be ground to fit any modern frames, like frameless glasses or glasses with curved lenses, so you can fully express your fashion sense.

  • We want more flexibility and relaxation especially when we're travelling. Which means self-tinting lenses can be a great travelling companion.

    However, you should bear in mind that a huge amount of UV rays are absorbed by a car's windshield, which has an effect on the lens performance. Fortunately, the PhotoFusion X lenses retain more of their self-tinting performance in the car than previous generations. Sunglasses are still recommended for longer trips.

    Photochromic prescription lenses also react to temperature differences, so self-tinting lenses darken less in bright sunlight when outdoor temperatures are high. As a result, we recommend carrying sunglasses in warmer areas.

  • Protection: Self-tinting lenses for all day UV and glare protection

    Whenever UV exposure comes up, reference is almost always made to its possible harmful effects. Excessive exposure to UV radiation can cause various types of damage to our eyes and skin.
    Harmful UV rays can enter the eye and reach the retina, which may lead to age-related macular degeneration.
    In addition, UV radiation may also cause cataracts, melanoma (the most commons cancer of the eye), sunburn on the cornea and various skin diseases. For this reason, UV protection is recommended all day long.
    Plus, self-tinting lenses protect the eyes against the annoying glare caused by bright sunlight.

Our tip when buying self-tinting lenses

There can be major differences in the quality and performance of self-tinting lenses. Ask your optician about the performance of self-tinting lenses:

  • How fast do photochromic prescription lenses darken?
  • How fast do they become clear indoors?
  • Do self-tinting lenses offer 100 per cent protection against harmful solar UV-A and UV-B rays?2
  • Do self-tinting lenses become totally clear indoors?
  • How dark can self-tinting lenses become in strong sunlight?
  • How do self-tinting lenses react in the shade?
  • How well do self-tinting lenses work in cars?

What eyeglass wearers have to say about PhotoFusion X, the self-tinting lenses by ZEISS

In September 2021, Carl Zeiss Vision did a consumer preference test with eyeglass wearers3 who tested PhotoFusion X lenses. Eight out of 10 of consumers prefer ZEISS PhotoFusion X gray over a well-known photochromic brand's latest generation gray.  Nine out of 10 of consumers find that PhotoFusion X lightens faster than the previous generation of PhotoFusion. And as many as  98  percent of consumers agree that PhotoFusion X lenses in their darkened state are dark enough to serve as sun protection lenses.


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  • 1

    Analyses by Technology and Innovation, Carl Zeiss Vision GmbH, DE, 2021. Measures on 1.60

  • 2

    Measures on Polycarbonate; All photochromic measurements in accordance to ISO 8980-3. Absorption is defined as 100% minus transmittance. Blue Violet Block (BVB) metric quantifies the amount of light 400-455 nm blocked by the lens. UV Protection% to 400nm is 100% minus the UV transmittance calculation defined by the Australia Standard® for Sunglasses and fashion spectacles (AS1067.2:2016) Photochromic performance is influenced by temperature, UV exposure, and lens material.

  • 3

    Consumer preference test with N= 101 eyeglass lens wearers in Germany in September 2021 by external market research institute (subjective visual assessment of lenses index 1.6 grey with AR coating, activated by artificial UV light source).