Is your eyesight fit for driving? The warning signs to look out for

From reading traffic signs to judging the distance to the car in front, it can be frightening finding your visibility is suddenly compromised when you’re behind the wheel. Many already experience anxiety when driving, so it’s equally nerve-wracking to think of the number of different ways it could happen – and how quickly. 

To help ensure you’re prepared, our experts have rounded up some of the different ways a driver’s vision could be impaired, and the best ways to overcome them with expertise from Specsavers.  

Blurred vision  

From serious conditions such as a detached retina, to more immediate causes like a migraine or even something as simple as high blood sugar, there are plenty of reasons you might suffer with blurred vision. When you’re on the road, however, one of the most common causes tends to be eyestrain.  

It makes sense when you think about it. Muscles strain under sustained pressure; our eyes are no different. Wearing sunglasses while driving in bright conditions can help, as can factoring some time into your journey to simply give your eyes a rest. But if you’re finding that you struggle regularly, speak with an optician about whether you should be wearing glasses or contact lenses when you’re out on the road.  

Distorted vision 

Just as with blurred vision, there’s plenty of reasons why your eyesight could become distorted. A head injury, retinal disease and even near or farsightedness can all play a role. If you’re behind the wheel, and find your vision becomes wavy unexpectedly, look for somewhere to stop and see if it will pass. If it starts to become a regular problem, consult a medical professional on whether it’s still safe for you to drive. 

Double vision 

In most cases, double vision is a symptom of squint, whereby a problem with muscles or nerves in the eyes cause them to look in slightly different directions. Squints tend to be more common in children and can actually be a sign of a more serious condition in adults. So, if you’re finding it’s a regular occurrence, seek professional advice. Likewise, suffering from double vision in just one eye is less common, and can, in some cases, be indicative of cataracts, whereby cloudy patches form over the front of the eyes.  

If you find yourself suffering with double vision, you shouldn’t drive until the DVLA has confirmed you’re allowed to go back on the road. It’s possible you’ll be allowed to wear an eye patch, to stop the double vision from occurring. But, like any other driver with vision in just one eye, you’ll need to demonstrate that you’re safe to do so. 

Rain   

There aren’t many road-going situations quite as frightening as being caught in a sudden downpour. Aside from the impact it can have on your handling and braking distance, heavy rainfall can also considerably reduce visibility. If there’s nowhere for you to stop until the rain lets up, try not to panic. Turn on your dipped headlights, so other drivers can see you, and avoid using your rear fog lights – these can mask your brake lights and might even dazzle the drivers behind you. Likewise, watch out for large or fast-moving vehicles, as the spray from their wheels can reduce your visibility even further. Slow down (if you can), be considerate of other drivers and just take it easy in wet weather.  

Sunlight 

At the opposite end of the spectrum, driving into dazzling sunlight can be just as challenging from a visibility point of view as driving through a downpour. The first thing to do is clean your windscreen – dirty glass can amplify a glare, as the dirt scatters sunlight. So even in the summer, it’s important to keep an eye on your washer fluid. Try to slow down and keep your distance from other drivers. As a way of planning ahead, it’s worth investing in a good pair of sunglasses that you can always keep in your car. 

Twitching   

While a twitching eye usually isn’t anything to worry about – often caused by stress, tiredness or just too much caffeine – it can still be problematic while you’re out driving. The best course of action, if possible, is simply to find somewhere you can pull over and take a break. If you’re pulling up at a service station, though, have some water, rather than a coffee! 

Watery eyes 

Most of the time, watery eyes are caused by an allergy, such as hay fever, or simply by having something like an eyelash or grit in your eye. There can be some slightly more serious causes, though, such as a blocked tear duct or even dry eye syndrome (which, despite its name, can cause your eyes to produce too many tears). If it’s something you know you tend to struggle with, keep some eyedrops or antihistamines in the car. For conditions that are more long-term, a GP or optician should be able to advise on whether it’s safe to be on the road. 

Hallucination 

Hallucinogens can severely disrupt your ability to focus on the road. As such, they should never be taken by anyone who’s planning on being behind the wheel. They can reduce your coordination and your reaction time, impair your judgement and, of course, significantly affect your vision. The bottom line really is quite simple – driving under the influence is never safe. 

Giles Edmonds, clinical services director at Specsavers, said:  

“There’s a whole host of factors than can impact your ability to see properly whilst driving. A wide range of these can be caused by environmental factors, but some of them are directly related to your eye health. It’s vital you get your eyesight tested every two years to make sure your eyes are performing as they should be.  

“You wouldn’t miss your car’s MOT – don’t skip a health check-up for your eyes either.”