Self-tinting lenses for more comfortable vision, flexibility and protection
Tips from BETTER VISION: who are photochromic prescription spectacle lenses by ZEISS ideally suited for and when should they be worn?
Modern self-tinting lenses, like ZEISS PhotoFusion X, can be a loyal and useful partner for all light conditions in your life. PhotoFusion X Lenses can be a useful all day partner, indoors and outdoors for changing light conditions making your life more comfortable. They are available in various fashionable colours and provide full protecion of harmful UV radiation. Let us show you for whom and in which vision situations photochromic prescription spectacle lenses can offer real added value.
A small but significant invention by chemist Stanley Donald Stookey and his colleague William Armistead in the 1960s made it possible to manufacture prescription spectacle lenses which 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.Â
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.
Even if the sun is shining outside, PhotoFusion® X is very clear in closed rooms and offers best vision.
We have compiled some tips to give you ideas of spectacle wearers and vision situations which are ideally suited for self-tinting lenses:
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Do you need your spectacles all the time? Does it bother you always having to carry two pairs of spectacles at all times so that you can see perfectly indoors and protect your eyes against glare and UV radiation outdoors when it is sunny? Spectacles with self-tinting lenses can make your life more comfortable, as you always have the right tint for all light conditions in one set of spectacles. PhotoFusion X prescription spectacle lenses with a high or medium refractive index darken in just 15 to 30 seconds in bright light or sunlight.1Â Indoors, they brighten again in 5 to 10 minutes1, becoming clear enough to see distinctly in a short time. Of course, they also offer 100 per cent protection against solar UV rays at all tint levels.
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Are you particularly sensitive to light? 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 on your eyes, as they adapt to the respective light conditions almost infinitely. In weak sunlight, they darken less, so that you can still see well in spite of the darkening.
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You  are used to have two pairs of spectacles - one clear lens solution for indoors and one sunlens for outdoors and you are annoyed changing spectacles all the time. For you, self-tinting lenses are the proper all day solution and no luxury, they can be an important tool to make you daily life easier and feeling more comfortable. Your spectacles quickly change from normal spectacles to sunglasses as soon as you walk from indoors to outdoors - and vice versa. You have the right lens solution for every light conditions no matter spending time indoors or outdoors, on sunny or cloudy days.
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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 spectacles. Self-tinting lenses mean that you are ideally equipped for any light conditions that occur right from the start. Your PhotoFusion® X prescription spectacle 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.
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One set of spectacles for all situations: Just as progressive spectacles can save you the trouble of constantly having to switch your reading glasses for your spectacles, so can self-tinting lenses save you constant switching between sunglasses and normal spectacles. Losing, forgetting or not knowing where to put your second pair of spectacles are now a thing of the past. Concentrate on the moment, and enjoy it – thanks to optimal vision in all light conditions.
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Your contact lenses – whether daily, monthly, annual or multifocal lenses – are your best friends. But there are situations where you need spectacles. However, you still want to be as free and active as before, e.g. during sporting activities. Sports spectacles 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.
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The times 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 colours - just like normal sun lenses. Self-tinting lenses can also be ground to fit any modern frame, like frameless spectacles or spectacles with curved lenses, so that you can live out your fashion taste fully.
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Especially when travelling, we want more flexibility and relaxation. Accordingly, self-tinting lenses can be a great travelling companion.
However, you should bear in mind that a huge amount of UV radiation is absorbed by the windshild which has an effect on the lens performance. Fortunatley, the PhotoFusion X Lenses retain more of their self-tinting performance in the car than previous generations. For long trips, sunglasses are still recommended.
Photochromic prescription spectacle lenses also react to temperature differences. That means that self-tinting lenses darken less in bright sunlight when outdoor temperatures are high. As a result, we recommend carrying sunglasses in southern countries in particular.
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When UV exposure is mentioned, reference is almost always made to its possible harmful effects. Excessive exposure to UV radiation can cause various damages to our eyes and skin. Harmful UV rays can enter the eye and reach the retina which can lead to age-related macular degeneration. In addition, UV radiation could also cause cataracts, melanoma (the most commons cancer of the eye), sunburn on the cornea and various skin disease. Therefore, UV protection is recommended all day long. Additionally, self-tinting lenses protect the eyes of annoying glare caused by bright sun light.
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 spectacle 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 spectacle 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 spectacle wearers3 who tested PhotoFusion X Lenses. 8 out of 10 of consumers prefer ZEISS PhotoFusion X grey over a well-known photochromic brand's latest generation grey.  9 out of 10 of consumers find PhotoFusion X faster in lighting than the previous generation of Photofusion. And as many as 98% of consumers agree that PhotoFusion X in their darkened state are dark enough as sun protection lenses.
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1
Average value for 1.67 and 1.6 and prescription spectacle lenses made of polycarbonate. Performance varies according to material, temperature and the light conditions.
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2
UV rays are divided into three categories, of which only UV-A and UV-B rays reach the earth's surface. The short-wave, energy-rich UV-C rays (100 to 280 nm) are absorbed almost fully in the earth's atmosphere. When we refer to solar UV rays, we only mean the UV-A and UV-B rays which reach the earth. The UV-A and UV-B rays are absorbed by the eyes to different degrees.
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3
Consumer preference test with N= 101 spectacle 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).