Modern self-tinting lenses, like PhotoFusion® by ZEISS, can be useful in all light conditions. 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 who should getphotochromic prescription eyeglass lenses and in which vision situations they 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 eyeglass lenses which react to UV rays. Now, high-performance self-tinting lenses are available, such as PhotoFusion® by ZEISS, which become as dark as sunglasses very quickly, and become totally clear indoors. ZEISS prescription eyeglass lenses with PhotoFusion® offer 100 percent protection against harmful UV-A and UV-B rays, as well as pleasant, natural and contemporary color tints. Despite this, many eyeglass wearers are reluctant to wear self-tinting, or photochromic, prescription lenses, because they believe that the prescription lenses do not adapt the tint to the light conditions fast enough. The image factor can also play a negative role as many eyeglass wearers find self-tinting lenses old-fashioned and frumpy.
Do you need your glasses all the time? Does it bother you to always have to carry two pairs of glasses at all times so that you can see perfectly indoors and protect your eyes against glare and UV rays outdoors when it is sunny? Eyeglasses 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 glasses. PhotoFusion® prescription eyeglass 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 percent protection against 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 various light conditions almost infinitely. In weak sunlight, they do not become fully dark like sunglasses, so that you can still see well despite the darkening.
You have had a long working day. You wear glasses and have to move between outdoors and indoors frequently for your job. Changing glasses 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 not a luxury; they can be an important tool, even if your vision problem is minor. Your glasses quickly change from normal eyeglasses to virtual sunglasses as soon as you change move 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 glasses. Self-tinting lenses mean that you are ideally equipped right from the start for any light conditions that may occur. Your PhotoFusion® prescription 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-A and UV-B rays, andthe best thing is that they improve 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 glasses, it can be advisable and far more convenient to give your child glasses with self-tinting lenses. That way you can be sure that your child is protected against harmful 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 glasses.
One set of glasses for all situations: Just as progressive eyeglasses can save you the trouble of constantly having to switch your reading glasses for your regular glasses, so too can self-tinting lenses save you from constantly switching between sunglasses and normal glasses. Losing, forgetting or not knowing where to put your second pair 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 for which you need glasses. However, you still want to be as free and active as before, like during sporting activities. Sports glasses 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 time when self-tinting lenses looked old-fashioned and frumpy is long gone. Contemporary self-tinting lenses, like PhotoFusion® by ZEISS, are available in natural, modern colors - just like normal sunglass lenses. Self-tinting lenses can also be ground to fit any contemporary frames, and can be used in frameless glasses or glasses with curved lenses as well, so that you can fully live out your fashion taste.
We want more flexibility and relaxation, especially when traveling. Accordingly, self-tinting lenses can be a great traveling companion.
However, you should bear in mind that most of the UV rays which activate self-tinting lenses are blocked by car windows, meaning that the prescription lenses do not darken as much there. Although PhotoFusion® prescription eyeglass lenses offer a certain protection against glare in cars, we still recommend wearing "real" sunglasses during long journeys with significantly changing light conditions (like through tunnels).
Photochromic prescription 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, particularly in southern regions.
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 eyeglass lenses which offer permanent UV protection and adapt to light conditions can be a real benefit for you. Your eye care professional can help with your decision.
There can be major differences in the quality and performance of self-tinting lenses. Ask your eye care professional about the performance of self-tinting lenses:
In November 2012, Carl Zeiss Vision conducted a study of eyeglass wearers** who tested PhotoFusion®. 9 out of 10 wearers rated the quality of PhotoFusion® as very good or good. 4 out of 5 were very satisfied or satisfied with PhotoFusion®. And, as many as 83% would recommend prescription eyeglass lenses with PhotoFusion® by ZEISS to their friends and colleagues.
*Average value for 1.67 and 1.6 and prescription eyeglass 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 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 at varying degrees.