To meet the challenges of everyday life, we need hard, dirt-resistant lenses that are easy to clean. This is precisely what hard, anti-reflective lens coatings offer – but the quality of these coatings can vary greatly.
What makes ZEISS lenses with DuraVision® Platinum AR coating different? These hard and light lenses are very robust, dirt-resistant and easy to clean while offering first-rate anti-reflective properties. An integrated system of coating layers densely packed using ion-assisted deposition results in a lens surface that is three times harder than the previous generation of hard anti-reflective (AR) coated plastic ZEISS lenses and 35 % harder than AR coated glass ZEISS lenses*. ZEISS lenses with DuraVision® Platinum AR coating also have a more cosmetically attractive, blue residual reflection colour that generates over 20% less luminous reflectance than conventional green AR coated ZEISS lenses.
ZEISS lenses with DuraVision® Platinum AR coating are three times harder than the previous generation of hard anti-reflective (AR) coated plastic ZEISS lenses1 and 35 % harder than AR coated glass ZEISS lenses.2
The patented anti-static layer3 prevents the build-up of static electricity. As dust and lint are not attracted to the lens surface, lenses stay cleaner longer.
The super-slick Clean Coat makes lenses very easy to clean. Lenses with high contact angles repel oil and water more effectively. ZEISS lenses with DuraVision® Platinum AR coating have a contact angle of a minimum of 110° (lenses without super-slick clean coat: 95°).
A less noticeable and blue reflection colour increases the light transmitted by the lens, resulting in even better vision. These lenses show more than 20% less luminous reflectance than conventional green AR coated ZEISS lenses.
Made up of nine ultra-thin layers, an integrated system of coating layers densely packed using ion-assisted deposition results in a lens surface that is three times harder than the previous generation of hard (AR) coated plastic ZEISS lenses1 and 35 % harder than AR coated glass ZEISS lenses.2
Ions transfer their kinetic energy to the coating molecules when these strike the lens surface.
The result: the coating's layers are more densely packed.
Why compromise on hardness, dirt-resistance and easy cleaning when you can have new ZEISS lenses with DuraVision® Platinum AR coating?
1. What exactly is a “hard” lens?
Lenses need to be robust enough to resist damage in daily life. The harder the lens surface, the more robust the lenses are.
2. How is lens hardness defined?
To find the best ways to make the hardest ever ZEISS AR coating for DuraVision® Platinum, we looked at:
- Other high-tech industries
- The everyday life of a spectacle wearer
3. How does DuraVision® Platinum perform in terms of hardness?
DuraVision® Platinum outperforms previous generations of ZEISS AR coatings in:
- High-tech hardness testing
- Real-life simulation tests
- The Bayer ratio
Following the measurement setup as described in DIN ISO 14577 we used an indentation instrument to determine two critical properties of DuraVision® Platinum:
The technology: a high-resolution nano-indenter
What we improved: surface hardness and crack-resistance of the coating
Similar technology has been used internationally in many different industries in which the hardness of material surfaces plays an important role, e.g. in the development and production of modern precision tools. But so far, it has not been applicable to lenses.
At the forefront of research:
Indentation equipment precise enough for the extremely thin coating layers on spectacle lenses has just recently been developed and was immediately integrated into the ZEISS research lab to help create the hardest ever ZEISS AR coating – DuraVision® Platinum.
In daily life, most scratches occur when lenses are cleaned with a cloth that has dirt on it, either from abrasive dirt particles that are on the lens when the wiping starts or from dirt particles that are already in the cloth. In the SDWT we use an artificially soiled cloth to simulate damage caused by lens cleaning:
- Cleaning procedure using standardized dust to soil cleaning cloth
- Improvement in scratch resistance from previous generations of ZEISS AR coating to DuraVision® Platinum after 600 wipes with 4 kg pressure.
- The Bayer ratio is a measure of the abrasion resistance of a (coated) surface to an oscillating abrasive medium (defined sand or similar).
- The surface damage is assessed via the increase in scattered light resulting from the surface damage.
- Different procedures for such a test are in place.
- We follow the procedure set forth by the COLTS laboratory in the U.S.
- (COLTS is the supplier-independent ophthalmic lens testing facility in the U.S.).
3 times harder than previous generation of ZEISS lenses with AR coatings and 35% harder than ZEISS glass lenses
The use of an electron microscope with 3000x magnification makes the advantages of DuraVision® Platinum clearly visible. While the previous generation of ZEISS coatings tears and peels, DuraVision® Platinum only shows fine lines. Less scattered light is generated and a higher Bayer ratio is achieved.
To offer patients true protection, ZEISS has developed an additional anti-reflective layer on the back of the lens, reducing the indirect light reflected into the eye and complementing the protection offered by ZEISS UVProtect Technology in all clear plastic lenses which blocks direct UV rays from the front.
More than 90% of UV radiation comes directly from the front. However, a minor part comes in indirectly from the sides and back. As some UV rays may be reflected onto the eye by the back surface of the lens, ZEISS antireflective coatings are designed to have low reflectance in the UV spectral range.
Back surface UV protection is now integrated as a standard feature into all premium ZEISS DuraVision coatings and the LotuTec coating.
ZEISS is one of the world’s leading manufacturers of eyeglass lenses, and is committed to delivering maximum precision and comfort. ZEISS designs and produces lenses, instruments and measurement systems, as well as retail concepts and technology services that continue to raise the bar in vision care.