Most of us are aware that driving at night is more demanding and stressful than driving in the daytime. We make natural compensations for this as we drive but it is a fact that the number of night and road accidents is much greater than those that occur during the day.
Road lighting levels at night are obviously lower than those found by day. This causes the pupil of the eye to become larger during night driving than under brighter conditions and the increase in pupil size can accentuate any existing small errors in focusing, causing blur. If you notice such a blur, your current glasses or contact lenses may need changing or you may need an optical correction.
The most common reason for haloes and reflections is a dirty windscreen (both inside and out). In the same way scratched or dirty spectacle lenses can contribute to unwanted scattered light, as can condensation on any of these surfaces.
It is a good idea always to clean your windscreen and glasses before night driving. Reflections from the surfaces of spectacle lenses can sometimes cause multiple images of lights at night. If you notice these, effective anti-reflection lens coatings are available.
Unfortunately a variety of changes in the eye can contribute to discomfort from glare during night driving, particularly among older drivers. This is commonly caused by cataracts which produce effects similar to looking through a dirty window.
Spectacles can do nothing to overcome this and it may be sensible to minimise night driving. If you are affected by oncoming headlights, try concentrating on the nearside kerb as you drive – but don’t forget to reduce your speed!
There is no evidence that these lenses improve vision on the road, indeed tinted lenses may actually make vision worse. Windscreen tints have the same effect and this is why the Highway Code warns drivers not to use any form of tint at night.
Make sure that your eyes are examined regularly
Always wear an up-to-date pair of distance spectacles or contact lenses
Keep a spare pair in the car if possible
Do not use tinted lenses but have them anti-reflection coated if necessary
Don’t forget to keep the windscreen clean, inside and out, at all times