Modern self-tinting lenses, like ZEISS PhotoFusion, can be a loyal and useful partner for all light conditions in your life. They make seeing less strenuous and more comfortable, while also offering your eyes 100% UV protection and meeting all your fashion needs. Let us show you for whom and in which vision situations photochromic prescription spectacle lenses can offer real added value.
A cloudy day with no obvious sunshine: PhotoFusion still protects the eyes against harmful solar UV rays.
When outside, PhotoFusion lenses darken according to the sunlight giving 100% solar UV protection.
Even if the sun is shining outside, PhotoFusion is very clear in closed rooms and offers best vision.
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, which become as dark as sunglasses very quickly, and become totally clear indoors. ZEISS prescription spectacle lenses with PhotoFusion offer 100 per cent protection against harmful solar UV-A and UV-B rays and pleasant, natural and modern colour tints. In spite of this, many spectacle wearers are reluctant to wear self-tinting, or photochromic, prescription spectacle lenses, as they believe that the prescription spectacle lenses do not adapt the tint to the light conditions fast enough. The image factor can also play a negative role as many spectacle wearers find self-tinting lenses looking old-fashioned and frumpy.
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 rays 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 prescription spectacle lenses with a high or medium refractive index darken in just 15 to 30 seconds in bright light or sunlight*. Indoors, they brighten again in 5 to 10 minutes*, 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.
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 strain on your eyes, as they adapt to the respective light conditions almost infinitely. In weak sunlight, they do not become fully dark like sunglasses, so that you can still see well in spite of the darkening.
You have had a long working day. You wear spectacles and have to move between outdoors and indoors frequently for your job. Changing spectacles all the time is frustrating and you often forget or do not have a hand free. Your eyes become strained and have a burning sensation in the evening. For you, self-tinting lenses are no luxury, they can be an important tool - even if your vision problem is minor. Your spectacles quickly change from normal spectacles to virtual sunglasses as soon as you change your workplace from indoors to outdoors - and vice versa. You have the right optical tool for every job, and your eyes will appreciate that.
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 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 solar UV-A and UV-B rays, while the best thing is that they improve your vision contrast and reduce glare.
Children's eyes are even more sensitive to UV rays than adult eyes, as they are still developing and let in more light. As a result, children actually need daily UV protection for their eyes. If your child wears spectacles, it can be advisable and far more convenient to give your child spectacles with self-tinting lenses. That way you can be sure that your child is protected against harmful solar UV-A and UV-B rays around the clock and can still see clearly and without strain in every light situation, without having to juggle two pairs of spectacles.
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.
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 light or shade, you always have the right tint, UV protection, and can see with more contrast while experiencing less glare. You only need one vision aid for relaxed vision.
The times when self-tinting lenses looked old-fashioned and frumpy are long gone. Modern self-tinting lenses, like ZEISS PhotoFusion, 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.
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 most of the UV rays which activate self-tinting lenses are blocked by cars' windscreens, which means that the prescription spectacle lenses do not darken as much there. Although PhotoFusion prescription spectacle lenses offer a certain protection against glare in cars, we still recommend wearing "real" sunglasses during long journeys with significantly changing light conditions (e.g. through tunnels).
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.
Do you often suffer from eye inflammation, chronic conjunctivitis or dry and sensitive eyes? Maybe you should protect your eyes against bright light and UV rays in particular. Prescription spectacle lenses which offer permanent UV protection and adapt to the light conditions can be a real benefit for you. Your ophthalmologist or ophthalmic optician can help with your decision.
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***?
- 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?
In November 2012, Carl Zeiss Vision conducted a study with spectacle wearers** who tested PhotoFusion. 9 out of 10 spectacle wearers rated the quality of PhotoFusion as very good or good. 4 of 5 of the surveyed spectacle wearers were very satisfied or satisfied with PhotoFusion. And as many as 83% would recommend prescription spectacle lenses with ZEISS PhotoFusion to their friends and colleagues.
*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.
**Source: Independent consumer study, Germany, November 2012
***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.