Police have been out and about today asking motorists to stop and read the registration plate of a vehicle parked 20.5 metres away - the legal standard set by the DVLA.
They are warning that drivers who fail this roadside eyesight test could have their licence revoked instantly.
Many sailed through the spot-check - but for others it was a wake-up call, as our correspondent Carl Edwards reports.
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Starting at Cardiff Castle, they will meet members of the public before enjoying a taste of Welsh culture, sport and heritage.
The decriminalisation of cannabis for medicinal use for those suffering with Multiple Sclerosis and cancer will be debated by AMs today.
The Met Office has issued 'be aware' warnings. It says travel disruption is a possibility.