Drivers who fail to read a number plate from 20m (65ft) away when stopped by the police will have their licences revoked immediately. 

In the new crackdown officers from Thames Valley, Hampshire and West Midlands will test the eyesight of every motorist they stop throughout September. 

Data will be collected from each test and used to gain an improved understanding of the extent of poor driver eyesight. 

Officers can request an urgent revocation of a licence through the DVLA if they believe the safety of other road users will be put at risk if a driver remains on the road.

Sergeant Rob Heard, representing the police forces taking part in the campaign, said: “All of us require good vision to drive safely on our roads – not being able to see a hazard or react to a situation quickly enough can have catastrophic consequences.”

The power to revoke licences was launched in 2013 under Cassie’s Law, named after 16-year-old Cassie McCord, who died when an 87-year-old man misplaced management of his car in Colchester, Essex.

It later emerged he had failed a police eyesight take a look at days earlier, but an authorised loophole meant he was allowed to proceed driving.

The minimum eyesight standards for driving are published on GOV.UK.