Road Safety & Vision

A lack of correction can be dangerous on the road

At 50Km/h, a driver with poor vision can require an additional three seconds to clearly identify road signs.⁽²⁾

FONTI:

(1) 2013, Essilor R&D internal calculations for Taxi Drivers Study. Calculations done taking into account only the visual performances of the driver. For a road panel positioned on a straight road at a height of 4m, if a person with 1.0 visual acuity (capable to discern 2 points seen under an angle of 1 minute-arc) see a detail on a road panel at 100 mts, a person with 0.5 visual acuity (capable to discern 2 points seen under an angle of 2 minute-arc) will see the same detail at 50 mts.

Presbyopes have difficulties seeing at several distances

	Progressive lenses help you see street signs at a distance of 60m compared to 38m with multi-focal contact lenses.^*(2)
	*47,5 m is the required stopping distance when driving at 50km/h on a dry road.

FONTI:

(2) 1999, Owsley, C. et al., « Older Drivers and Cataract: Driving Habits and Crash Risk ». The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences.

Drivers with cataracts are 2.5 times more likely to have been involved in a crash.⁽³⁾

At 130kh/h, people with cataracts require an additional 0.35 seconds to react, increasing their stopping distance by up to 12 meters.⁽³⁾

FONTI:

(3) 1999, Owsley, C. et al., « Older Drivers and Cataract: Driving Habits and Crash Risk ». The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences

Glare can affect anyone in all conditions

During the day, by eliminating reflected glare, polarized lenses improve driver reaction time by up to 0.3 seconds.
At 130km/h, this reduces the stopping distance by up to 11 meters.⁽⁴⁾

FONTI:

(4) 2009, Zikos, G.A., et al., Contrast Sensitivity and Reaction Times with Polarized and Tinted Lenses in a Driving Environment. Association for Research in Vision and Opthalmology

Glare can affect anyone in all conditions

At night, after being blinding by incoming headlights, drivers will travel approximately 538m with limited vision when driving at 130km/h.⁽⁵⁾

FONTI:

(5) 1991, Patorgis CJ. et al., Photostress recovery testing, in: Clinical Procedures in Optometry, Eskridge J.B., Amos J.F., Bartlett J.D.

Color-blind people have admitted they have difficulty with traffic signals

	In sunny weather, the visibility of road signs for people with good vision is about 100m. For color-blind drivers, it is about 50m.^*(6)
	*47,5 m is the required stopping distance when driving at 50km/h on a dry road.

FONTI:

(6) Barry L. Cole, « Protan Colour Vision Deficiency and Road Accidents », Clinical & Experimental Optometry 85, no 4 (juillet 2002): 246‑53.