Abstract
Purpose :
Spectacle lenses for improvement of vision during night time driving have been introduced to the market a few years ago. The main purpose of those lenses is to reduce glare. Three options to achieve a reduction of glare are currently used: spectral manipulation especially of shorter wavelengths, purpose-adapted anti reflexion coatings or a combination of the afore mentioned approaches.
To enhance the knowledge, how driving lenses achieve their purpose, the spectral irradiance was compared.
Methods :
Four spectacle lenses for driving (refractive power of 0 D, refractive index 1.6) were evaluated (DriveSave, Zeiss, Germany; EnRoute PRO, Hoya, Japan; Formula Drive, Optovision, Germany and Streetlife, Essilor, France). A plano standard lens (refractive index 1.6) was measured as control. The spectral irradiance, within the wavelength range of 380 to 780 nm (step size = 5 nm), was measured using the Mavospec Base spectrometer (Gossen, Germany). The measurements were performed for three different conditions: a filament bulb, a white LED (peak at 455 nm) and a blue LED (peak at 410 nm) in a dark environment.
Results :
From the spectrograms it is visible that manufacturers use different approaches to reduce glare whilst driving.
For the filament bulb condition, no significant change of the spectral irradiance was observed for the DriveSave and Streetlife lenses. The EnRoute and Formluar Drive lenses appear as edge filters and start transmittance from 420 nm onwards. The standard lens appears similar, but transmittance starts at 410 nm.
For the white LED condition, no significant change of the spectral irradiance was observed throughout all lenses, except a reduction of the blue peak by about 5 mW/m^2 for the DriveSafe, EnRoute and Formula Drive lenses.
For the blue LED condition, the blue peak was reduced by 82 mW/m^2 by the Streetlife lens. The DriveSafe and standard lenses reduce the peak by 276 mW/m^2 and 455 mW/m^2, respectively. The EnRoute and Formula Drive lenses, however, nearly eliminate the blue peak (2,24 mW/m^2 and 7,95 mW/m^2, respectively).
Conclusions :
From the spectrograms of different lenses under different illumination conditions it is evident that various approaches are used to reduce glare whilst driving. As different approaches exist, it is important during patient consultations to test various lenses for driving and allow the patient to choose the lenses, which shows the best effect for each individual.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.