ZEISS DriveSafe Lenses

The pupil reacts to light intensity from its surroundings, specifically the light that directly strikes the eye. In daylight conditions, the pupil diameter is small, whereas it is large at night. In low light, so-called mesopic conditions, i.e. twilight, rainfall, dark days or night driving, the pupil diameter is in-between small and large. Space perception, as well as distance assessment, becomes more difficult for the driver.
After intensive research in the field of mesopic vision*, the rationale for the development of ZEISS Luminance Design™ Technology was identified and verified during wearer trials. In a nutshell: there is bright light (photopic vision), no light (scotopic vision) and in-between low light (mesopic vision). In mesopic conditions, the light intensity, and thus the pupil size changes: a challenge for visual performance.

_{*For more information please refer to the ZEISS DriveSafe White Paper}

ZEISS developed the new Luminance Design® Technology (LDT), which takes into account different light conditions and pupil sizes to improve the lens design for natural vision at all times. LDT incorporates the pupil size for driving in mesopic conditions and optimises the lens design accordingly: the adapted pupil sizes used in the optimisation algorithms are 5.0 mm in single vision lenses and 4.3 mm in progressive lenses.

As a result, wearers have better vision in low-light conditions.

Glare describes the difficulty of seeing in bright light, such as direct sunlight or artificial light. Market research and scientific evidence both indicate that perceived glare in traffic is linked in particular to LED and Xenon HID light sources as used in modern car lighting technology. Intense glare can be a risk, as it reduces the visibility of objects and sensitivity of the eye to contrast. Glare also can be subjectively perceived as discomfort and irritation.

ZEISS vision science researchers carried out glare experiments. These formed the basis of internal studies* using different coating simulations. Scientific evidence shows that the blueish, high-energy part of the visible spectrum (in particular in the 440–470 nm range) using LED or Xenon H.I.D. (High Intensity Discharge) technology is linked to a glare effect perceived by drivers.

_{*For more information please refer to the ZEISS DriveSafe White Paper}

DuraVision^® DriveSafe Coating by ZEISS partially reflects these wavelengths, which reduces perceived glare up to 64%** compared to premium AR coatings.

_{**Compared to premium ZEISS coatings. With DuraVision DriveSafe 64% less test drivers reported issues with glare with the new coating than with other premium AR coatings.}

Driving demands a high level of concentration from drivers. Most of the time they need a broad view of the road in order to evaluate traffic conditions. The situation becomes challenging, especially for progressive lens wearers, when they need to switch their focus between the road, dashboard and mirrors. That is when dynamic vision becomes essential.

In an eye tracking study with FKFS* we identified the vision field needs of drivers:

• 97% of the recorded time they watch the road.
• 2% of the recorded time they use to look at the dashboard.
• 1% of the recorded time they switch focus between mirrors.

_{*FKFS Research Institute of Automotive Engineering and Vehicle Engines Stuttgart is an independent foundation associated with the University of Stuttgart. Founded in 1930, FKFS has become one of the largest and leading research institutes in the field of automotive engineering, serving major automobile manufacturers and suppliers. For more information please refer to the ZEISS DriveSafe White Paper.}

To make it easier for progressive lens wearers to quickly refocus between the road, dashboard and mirrors, ZEISS developed the new DriveSafe Progressive Lenses with optimised distance and intermediate viewing zones, reducing the need for horizontal head movement.

• Dynamic vision for fast refocusing from the road to the dashboard and mirrors
• Near viewing zone ideally suited to daily activities
  

Up to 43% larger** mid-distance zone for easier focus switching between the dashboard and mirrors. And up to 14% larger** far-distance vision zone for a wider view of the road.

_{**Compared to ZEISS premium progressive lenses}