Most drivers know the police can breathalyse them.
Far fewer realise that an officer can also ask them to read a number plate at the roadside — and failing that test can put their driving licence at risk almost immediately.
The current legal standard for a car or motorcycle driver includes being able to read a modern registration plate in good daylight from 20 metres, using glasses or contact lenses if necessary. Drivers must also meet minimum visual-acuity and field-of-vision requirements.GOV.UK: Driving eyesight rules
The police have the power to require the number-plate test. An electronic notification system allows DVLA to revoke a licence following a failed roadside eyesight test in a matter of hours. DVLA: Safer drivers, safer roads
For somebody who depends on driving for work, that is a very different problem from waiting for points to arrive after a prosecution.
The number plate is only the roadside test
Being able to read the plate from 20 metres is the part most drivers recognise.
The full eyesight standard goes further.
For ordinary car and motorcycle licences, GOV.UK says drivers must also have visual acuity of at least 6/12 on the Snellen scale, using both eyes together or the only eye where applicable, and an adequate field of vision. GOV.UK: Visual disorders and fitness to drive
If glasses or contact lenses are needed to meet the standard, they must be worn whenever you drive.
There are also eye conditions which have to be reported to DVLA in particular circumstances. GOV.UK warns that failing to notify DVLA about a medical condition affecting your driving can result in a fine of up to £1,000, with the possibility of prosecution following an accident caused by the condition. GOV.UK: Eye conditions and driving
For professional drivers, the standards are higher again. Bus and lorry drivers have stricter visual-acuity and field-of-vision requirements, so a problem with eyesight can have an immediate effect on someone’s ability to earn a living.
Roadside eyesight enforcement is receiving renewed attention
Eyesight and driving have been back on the Government’s agenda this year.
In January 2026, the Department for Transport opened a consultation on introducing mandatory eyesight testing for drivers aged 70 and over when renewing their licences. The consultation closed on 11 May 2026. Department for Transport eyesight consultation
The evidence behind it was striking.
A roadside vision-screening exercise involving 3,010 drivers and riders in England and Wales found that 1.7% of those stopped failed the number-plate test. In total, 1.4% had their driving licences revoked, including 38 immediate revocations. Among motorists aged 81 to 90, 10.2% failed. (GOV.UK)
This is not simply an issue for elderly drivers. The legal eyesight standard applies whenever you drive.
Revocation and prosecution are different issues
A driver who fails a roadside eyesight test may understandably focus on getting the licence back.
There may also be a criminal allegation to deal with.
Section 96 of the Road Traffic Act 1988 provides for an offence of driving with uncorrected defective eyesight. It also gives a constable who has reason to suspect the offence power to require an eyesight test.
What follows will depend on the individual circumstances: why the driver was stopped, what happened during the test, whether corrective lenses were required, the driver’s medical position and whether any separate road traffic allegation is being investigated.
A licence being revoked by DVLA is therefore not something to confuse with the prosecution process itself.
For a taxi driver, delivery driver, tradesperson, salesperson or business owner, both need to be understood quickly.
Road Traffic Defence represents motorists throughout Scotland and specialises in protecting driving licences and livelihoods. If the police have become involved, the sensible time to understand the legal position is before making assumptions about what happens next.
If you have failed a roadside eyesight test, had your licence revoked or been accused of driving when your eyesight did not meet the legal standard, find out exactly what you are facing before deciding what to do next.
Call Road Traffic Defence on 0800 11 12 13 or book an initial appointment with Road Traffic Defence.
