How does a photochromic lens work?
In lenses that darken in the light, trillions of molecules start to change their structure as soon as they are exposed to UV light. This causes the lenses to darken and adapt automatically and instantly to the constant light conditions. The stronger and brighter the sunlight, the darker the lens becomes, and vice versa. So it can change at any time.
Light transmission of darkening lenses
The light range of such lenses is truly unique, with different lenses being able to vary their light transmission between 10%-90%. As they tint to UV light, it is clear that they also have excellent UV filtering properties. The most common variations are grey and brown, but there is now also a green version available from Rodenstock ColorMatic lenses.
ZEISS PhotoFusion photochromic lenses
If you’re looking for a new and comfortable pair of glasses that guarantee perfect vision in any light, day or night, ZEISS light-darkening lenses are an excellent choice. Not only does it provide 100% protection against UV rays, but it also adapts to our daily activities in changing light conditions. The ZEISS PhotoFusion® high and medium refractive index effective light-darkening lens also delivers the quality you’ve come to know and more, and goes from dark to light twice as fast as previous models.
Cutting-edge technology for excellent performance
Based on a recent ZEISS survey, wearers have clear criteria for both quality and performance when it comes to light-darkening lenses:
All of these requirements were taken into account by ZEISS when creating PhotoFusion® high and medium refractive index light-darkening lenses. These darken in just 15-30 seconds as soon as you walk into glare or the sun. And when indoors, they go completely clear in 5-10 minutes.
Performance in these situations depends on the material, the temperature and of course the lighting conditions. All these factors make PhotoFusion® a deserved leader among light-darkening lenses. It also offers 100% protection against the sun’s UV rays.
Transitions tinted lenses
Transitions Optical is the only optical company to have two proprietary and patented technologies for darkening to light. Thanks to these, the darkening pigments form a complete, integral unit with the lens. It also guarantees reliability and global leadership worldwide.
Breakthrough technology, a new frontier in performance
One of the technologies is called “infiltration”, which comes from the Latin word imbibere – to infiltrate. This method uses heat to incorporate pigments that darken to light into the lenses. Once this is done, the lenses are given a scratch-resistant coating.
The other is the so-called Trans-Bonding™ process, which uses a technology that darkens to light on the surface of the lenses, as opposed to the “embedding” process just described, where this happens below the surface of the lenses. This may be necessary in many cases because many lens substrates are too difficult to absorb darkening pigments.
Unlike some other methods of darkening lenses, both methods provide a uniform tint on the surface of the lenses, regardless of their diopter or thickness. At Transition Optical, they place a high priority on continuous improvement of the process to achieve the best possible results in terms of optimal light-darkening, lens durability and compatibility with other lens treatment methods, such as when a reflective coating is added.
Transitions XTRActive photochromic lenses
When driving, most lenses that darken to light do not darken noticeably, as more than 99% of UV light is absorbed by the glass in the windscreen of a car. Transitions XTRActive lenses contain specially designed light-darkening formulas that can adapt to light conditions in the car. This is due to the fact that they respond not only to UV light but also to short wavelength visible light, making these lenses really comfortable to wear.
These lenses are available in a range of colours. While they will tint to an extra darker shade outdoors, they will be lighter in the car and change to a pleasant, even lighter shade indoors. In all conditions, they provide 100% protection against UVA and UVB rays.
Transitions Drivewear photochromic lenses
The previous photochromic lenses simply could not be used for driving, as they were completely inadequate for the task. The windscreen filtered out most of the UV radiation, so the lens did not darken. The Transitions Drivewear lens, on the other hand, uniquely combines the properties of a polarised lens with the ability of a lens that darkens to light to respond quickly to changing light conditions.
This is achieved by maximising the amount of light that reaches the eye and optimising the amount of light that enters the eye, in all light conditions. Our eyes are thus relieved of uncomfortable strain, both when we are in direct light and when we are sitting in a car. In effect, it’s a polarised and a light-darkening sunglass in one, making it an excellent choice for driving.
The advantages of polarised lenses include the elimination of glare, for example, and a much more contrasty view than a conventional pair of sunglasses. So the amount of useful light that reaches your eyes is fully maximised. The fact that this lens takes on a yellowish-green tint when the light is slightly lower – for example, in the case of lamb’s wool clouds – also has a contrast-enhancing effect. When you are in bright light, the lens turns amber.
It also filters out distracting light reflections from wet roads, removes glare and highlights colours like green and red, which are very important when driving – think of traffic signs or lights. It also gives maximum filtering of excessive light. In bright light, such as when you’re outdoors in the sun, the lens turns a dark reddish brown. This is when it darkens the most and the fastest. In summary, the Drivewear lens adapts perfectly to the visual conditions, providing optimal visual comfort for the wearer.
Rodenstock ColorMatic® photochromic lenses
Even if we take it for granted, it’s important to remember that our eyes are constantly working hard, non-stop. They have to adapt to changing light conditions, whether it’s twilight, glaring sunlight or artificial light. To support our eyes and achieve more comfortable, relaxed vision, photochromic lenses can help.
Fast response time, maximum protection
The most modern light-darkening lenses must meet three main criteria. These are speed, protection and colour. The new range of Rodenstock ColorMatic® lenses perfectly and fully meets these requirements.
The greater the speed of darkening, the more comfortable it is to wear a lens that darkens to this light. ColorMatic IQ® lenses are particularly good at this, darkening and brightening in a very short time. This effectively helps the physiology of the eyes. Wearing them guarantees comfortable, relaxed vision even for those who wear sensitive glasses.
For this model, we have an impressive choice of colours. Starting with warm brown, which both soothes the eyes and enhances contrast in darker conditions. The cool grey gives a completely natural colour effect, so its strength lies in its neutrality and the balance it achieves. We should also mention the colour green, which enhances contrast and has a calming and soothing effect. Whichever colour you choose, they all brighten up interiors, while providing the best protection when faced with glare, such as sunlight.