Is Your Eyesight Legal For Driving? Vision Requirements For UK Drivers

There are a wide range of eyesight conditions that could affect your vision and ability to drive — especially in the eyes of the law. 

So, is your eyesight legal for driving in the UK? Let’s dig into the detail and find out. 

Driving eyesight: rules and regulations

To legally drive a car in the UK, the law requires you to: 

• Be able to pass a roadside eye test (more on that later) 
• Always wear glasses or contact lenses if you need them to achieve an adequate field of vision of at least 120 degrees and 0.5 on the Snellen scale
• Tell DVLA if you’ve got any problems with your eyesight that affects both of your eyes — excluding being short/long sighted or colour blind

If you drive a bus or lorry, you must also: 

• Have a visual acuity of at least 0.8 (6/7.5) measured on the Snellen scale in your best eye and at least 0.1 (6/60) in the other eye 
• Be able to reach that standard using glasses with a corrective power of no more than (+) 8 dioptres, or with contact lenses of any corrective power 
• Have uninterrupted horizontal vision field of at least 160 degrees with an extension of at least 70 degrees left and right, and 30 degrees up and down 
• Have no defects in your vision within a radius of the central 30 degrees  

If you don’t tell the DVLA about a condition that affects your eyesight and/or ability to drive, you can be fined up to £1,000 and may be prosecuted if you’re involved in an accident as a result. 

Click here for a full list of conditions that you are required to inform the DVLA about. Examples include cataracts, glaucoma and macular degeneration that individually, or in combination, affect both eyes — as well as conditions like dementia and Parkinson’s disease. 

What is the Snellen scale?

The Snellen scale is used to measure visual acuity: the clarity and sharpness of your central vision. It consists of rows of letters that get smaller as you read the chart. If you drive a bus or lorry, you are usually required to take a Snellen test every five years. 

Roadside eye tests

Every driver in the UK must be able to pass a roadside eye test. These test a driver’s ability to read the number plate of a parked car that’s 20 metres — the equivalent of five cars — away. You can take this test while wearing any glasses or contact lenses you need. 

When you take your driving test, you’ll be asked to complete a roadside eye test before getting into the car. If you fail it, you’ll automatically fail your driving test and your provisional driving licence will be revoked. 

You might be asked to take this test (and others) whenever you renew your driving licence, which will be every three years after the age of 70. 

Under Cassie’s Law, the police also have the power to ask for an urgent revocation of your driving licence if you cannot pass a roadside eye test at their request. This power was introduced in 2013, after the death of Cassie McCord, who died when an 87-year-old man lost control of his vehicle. 

4 factors that can affect your eyesight 

Here are some of the most common conditions that could impact your ability to drive. 

Diabetes

Diabetes can lead to diabetic retinopathy, which is when damaged blood vessels in the back of the eye start bleeding, due to high blood sugar levels. This can destroy your sharp vision and eventually lead to partial vision loss or blindness. 

Cataracts

Cataracts are when the small transparent disc in your eye (the lens) develops cloudy patches, usually when you age. If untreated, these patches can grow and cause blurry vision, partial vision loss and complete blindness. 

Age-related conditions

Cataracts aren’t the only age-related condition that can affect your eyesight. Others include:

• Macular degeneration
• Presbyopia 
• Dry eyes 

Each of these can significantly impact vision, if left untreated. 

Glaucoma

Of all age-related eyesight problems, glaucoma is one of the most common. This is caused by extra pressure and fluid build-up in the eye, which can damage the optic nerve and lead to eye pain, vision loss, blurred vision and eventually blindness. 

What to do if your eyesight is getting worse 

If you notice your eyesight is getting worse, you must immediately seek treatment and inform the DVLA of your diagnosis. You must also stop driving until your vision improves and meets the required standard. 

Early signs that your vision is changing

Pay attention to the following symptoms: 

• Hazy, blurry or double vision 
• Persistent eye pain 
• Seeing flashes of light or bright spots
• Seeing halos around lights
• Swollen, red eyes
• White areas in the pupil of the eye
• Itchy, dry eyes 
• Any other change in vision/eye health 

If any of these occur, book an appointment with an optometrist and get in touch with the DVLA if necessary.