Vision and Driving

Three things usually combine. Early cataract scatters light, producing halos around headlights. Contrast sensitivity declines with age, making it harder to pick out a dark shape against a dark background. And pupils dilate at night, which exposes more of the peripheral lens and any optical imperfection in it.

All three are assessable, and most of what causes the difficulty has a solution.

Reflected glare from road surfaces and from light coloured desert ground is intense here, and a plain tint only reduces overall brightness. Polarised lenses specifically eliminate the horizontally reflected light that causes squinting, which is why they make so much more difference than a darker lens.

Worth knowing: photochromic lenses darken far less in a car, because windscreens block most of the ultraviolet light that activates them. For driving specifically, dedicated polarised sunglasses do the job better.

Glaucoma takes peripheral vision so gradually that the brain fills in the gaps, and people routinely lose a substantial share of their visual field before noticing. Visual field testing measures what you are genuinely detecting rather than what you believe you are seeing.

That is one reason regular examination matters for drivers specifically, and it is why any concern about your field of view should be assessed rather than assumed to be normal ageing.

If you are due a renewal and have any doubt about your vision, have an examination first. It is assessed properly here and discussed with you directly rather than left ambiguous.