Awards 2016: How DriveSafe scooped Lens Product of the Year

Optician looks at the technology behind Lens Product of the Year - the Carl Zeiss DriveSafe - to find out more about its motoring credentials

This year’s entries in the Lens Product of the Year category reflected the nature of modern day patient needs and the progress made in lens manufacturing.

Submissions ranged from the combination of iPad-based lifestyle analysis software and tailored progressive lenses from Waterside Laboratories to the latest freeform manufacturing technology found in the Shamir Attitude III.

In a hotly contested category, the winner was the DriveSafe lens from Carl Zeiss.

The DriveSafe lens was created to service the number of spectacle wearers that feel insecure, uncomfortable or stressed when driving, more so in difficult light and weather conditions, such as rain, twilight or night.

Research conducted by Carl Zeiss found that 83% of spectacle lens wearers drive and, of those, 72% were interested in an everyday ophthalmic lens solution specialised for driving. It was an underserviced sector of the market crying out for something different from existing driving sunglass solutions.

To make sure this was a true driving lens, it was designed from the ground up with the needs of motorists the sole focus. Initial research took place in collaboration with the Research Institute of Automotive Engineering and Vehicle Engines in Stuttgart. Researchers used a number of methods during their studies, including using advanced head, eye and visual scene tracking systems within the test cars to quantify visual behaviour.

Through consumer analysis, three common issues experienced by spectacle wearing drivers were indentified; poor visibility in low light conditions, glare from oncoming cars and difficulty switching focus between the road, dashboard and mirrors.

In low light or mespoic conditions, pupil diameter varies between small and larger, which hampers visual tasks such as space perception and distance awareness, along with visual acuity and contrast sensitivity. Additionally, off-axis aberrations of single vision and progressive lenses interact with the enlarged mesopic pupil to diminish retinal image quality further.

The manufacturer said its luminance design improved on other ophthalmic lens with better handling of light rays. Traditional lenses were said to only consider discrete light rays to determine the refractive distribution, but the DriveSafe considers the entire package of rays that pass through the mesopic pupil. As a result, DriveSafe single vision and progressive lenses are said to have a smoothened refractive profile that improves contrast and acuity by reducing off-axis aberrations and distortion as the eye moves.

Glare at night is probably one of the most common complaints practitioners hear about when talking about driving while wearing spectacles, so reducing the uncomfortable effects of glare was high on the list of priorities when designing DriveSafe. The nature of night driving means that the visual system must adapt quickly to differing levels. High luminance in the visual field, for example headlights from oncoming vehicles, causes harsh glare, while readaptation to lower light levels following glare exposure takes time.

During the recovery period, visual performance is reduced and recovery time itself increases as the exposure time to glare increases and vary with age say Carl Zeiss.

In collaboration with automotive light researchers L-Lab, the DuraVision DriveSafe coating has been designed to attenuate glare illuminance by partially reflecting the short wavelengths of blue light commonly found in car headlights, enhancing visual contrast and providing up to a 64% reduction in perceived glare when compared to Zeiss’ other MAR coatings.

During research at the Research Institute of Automotive Engineering and Vehicle Engines, engineers used head and eye tracking to establish heat maps of the driver’s gaze. Frequent eye and head movements were required to switch fixation between the road ahead, peripheral field, mirrors and instrument dashboard. A real-world driving course and an advanced full-motion driving simulator revealed drivers focus on the road ahead for 97% of the time, look at the dashboard for 2% of the time and use dynamic vision, switching focus between mirrors, for 1% of the time.

Progressive lens wearers exhibited longer eye and head movement path lengths, and a greater number of saccades when compared to single vision lens wearers, which could negatively affect some aspects of driving performance.

The DriveSafe progressive lens design uses an optimisesd vision zones to provide improved visual dynamics, with 14% extra width for distance vision to facilitate fast and accurate localisation of the mirrors. The intermediate zone is also expanded by 43% to enable easier switching between the dashboard instruments and other driving tasks.

On the win and the Optician Awards evening, Peter Robertson, marketing & communications director, Carl Zeiss Vision, said: ‘The Awards Ceremony was an inspiring event, and the first time the company has attended. It was great to see such strong representation and support from across the industry. The DriveSafe Lenses award was an extremely delightful surprise, and the recognition greatly appreciated by the organisation.’

Lens product of the Year 2016

Winner: DriveSafe, Carl Zeiss Vision
Shortlisted: Elysium Lens and Visual Lifestyle Analysis App, Waterside Laboraratories; Eyezen, Essilor; Glacier Coatings, Shamir UK