Just over a year ago I was driving back from Cumbria to Edinburgh. Just after leaving the M74, a Porsche SUV with LED headlights at the same height as my rear window approached from behind me, then followed me at a distance of about 20 yards. The glare from these headlights in my rear-view mirror was so bad it caused me physical pain in the eyes. I hurriedly turned my rear-view mirror askew to stop the pain, then pulled over as soon as I safely could to let the SUV pass. I needed to wait 10 minutes for my eyesight to recover and after readjusting my mirror I headed home to Edinburgh with a blinding headache.

It turns out I’m not alone. Research published by the RAC in March 2022 found 89% of drivers think that some or most vehicle headlights on the UK’s roads are too bright with 88% saying they get dazzled by them while driving. The problem is getting worse with 63 per cent saying it’s happening more often than a year or two ago and 64% thinking they risk causing other drivers to have collisions as well as 67% unable to tell if the headlights of oncoming vehicles are dipped or on full beam. Since 2013, there have been 293 accidents a year on average where dazzling headlights were a contributory factor.

The human eye has evolved to allow it to adapt to a wide range of light levels from bright sunlight to almost total darkness. But it cannot adapt in a short space of time. Comfortable vision requires a limited range of light levels at any particular time.

Katie Appleyard

Port Townsend