Enforcement of the new visual acuity standard for driving cars and motorcycles will rely on information being volunteered to the Driver and Vehicle Licensing Agency (DVLA).
Following the announcement of a Snellen standard (News 11.05.12), the DVLA has confirmed that from May 1 it was unable to license drivers who told them they had been advised their vision was below 6/12. The same applied to those found to be below this standard 'through other investigation', a DVLA statement said.
Road safety charity Brake welcomed the new standard but called for the removal of the number plate test, which was kept at 20 meters.
Stephen Belfield, campaigns and media officer at Brake, said: 'Brake urges the government to scrap the number plate test and replace it with a proper vision test with a qualified practitioner.
'Drivers would be required to show evidence of this when they take their test, at least every 10 years thereafter on renewing their photocard, and at renewal and 70 and thereafter.
'The government must also raise greater awareness among drivers that vision can deteriorate quickly, sometimes without you noticing, so you should get your eyes tested every two years or sooner if you notice problems. Only by ensuring regular testing, using a scientifically proven method, can the government prevent poor driver eyesight in the UK leading to devastating crashes and casualties.'
The DVLA has also revised the visual acuity standard for lorry and bus drivers to 6/7.5 in the better eye. It said that these drivers must pass a medical examination with a general practitioner to get their licence or, in some cases where vision standards could not be met, via a certificate of vision from an eye care professional.
However, the DVLA added that 'in the future an optician/optometrist completed certificate of vision will become part of the application and renewal process for bus and lorry licensing'.
Last week's changes were made to keep UK driver licensing standards in line with the EU minimum, and followed extensive campaigning by the optical profession.