Clear Vision, Safe Driving

As a minimum legal requirement, motorists must be able to read a numberplate from a distance of 20.5 metres (67 feet) and have a 120 degree wide field of view. This test is normally only carried out officially at the time of the driving test itself and recent research has shown that more than 10 per cent of drivers would fail a driving test if they re-took it today because of poor eyesight.

In law it is a driver's responsibility to ensure that they can pass the numberplate test at all times. They must also be able to see clearly out of the corners of their eyes, see clearly at night and not have double vision. It's important to remember that if you fail to meet these visual standards you are breaking the law every time you start your engine.

For drivers, the importance of having a regular eye examination (at least every two years) is obvious, particularly bearing in mind that people's eyesight changes over time.

If you do need to wear spectacles or contact lenses to meet the visual standard for driving, it's vital to ensure you wear them at all times. This may sound obvious but every day tens of thousands of motorists drive without their glasses because of vanity, or because they have forgotten them, or because they are only driving a short distance. No matter what the reason, these people are breaking the law and are a potential danger to themselves and other road users.

Essential Checks To help you see the road ahead more clearly, ensure that your windscreen is clean and scratch-free, both inside and out, at all times. Your car lights are important so make sure that the headlamp glass is clean, the bulbs are working at full strength and your lights are properly adjusted to provide good road illumination while not causing glare for other road users.

Look slightly to the left of oncoming traffic at night to avoid suffering from glare which can take some time to recover from.

Drivers' Eyewear
Some spectacles are better than others for driving, with rimless designs or those with thin rims being particularly suitable as they allow greater all-round vision than those with heavy frames. Spectacles with plastic lenses are lighter and safer. Anti-reflection coatings can be applied to any lenses at a reasonable cost, helping you to see more clearly and cut down on glare, especially when driving at night.

Make sure you keep your spectacles and contact lenses clean at all times - it's best to keep a cleaning cloth in the car. It's also sensible to keep a spare pair of glasses in the car so that you never forget them. This is also important if you normally wear contact lenses because on long journeys when your eyes get tired it is often more comfortable to switch to a pair of glasses. It's also a useful safeguard if you suffer from hay fever.

It's worth remembering that in some countries it is a legal requirement to keep a spare pair of glasses or contact lenses in the car.

Sunglasses
If you need to wear prescription glasses to drive, never replace them with non-prescription sunglasses when it is sunny. It is dangerous and you will be breaking the law. Instead, get a pair of prescription sunglasses (which need look no different to normal sunglasses) or clip-on lenses over your prescription lenses. When using clip-on sunglasses make sure you check their suitability for plastic lenses.

The Law says that you should never use tinted glasses at night. Nor should you use them in conditions of poor visibility such as heavy rain, fog and snow showers. This rule also applies to sunglasses and tinted motorcycle helmets.

Drink and Drugs There are factors that can impair a driver's eyesight temporarily. For example, alcohol can reduce your vision as well as slowing your reactions to potentially dangerous situations and can cause drowsiness even when the driver is below the legal alcohol limit. Some drugs or medicines can also reduce or impair your vision so you should always check with your doctor whether a prescription is safe for driving. Tiredness, particularly on long journeys, can reduce your ability to see clearly.