Drivers who were stopped for speeding were asked to take part in an eyesight test during an awareness campaign in May by Bucks County Council and police.
The majority passed with no problem, but three drivers had difficultly reading the number plate and were advised to visit their optician as a matter of urgency.
The law requires all drivers able to read, in good daylight, with glasses or corrective lenses if needed, a number plate from 20 metres away.
Motorists could be prosecuted for driving if they don’t meet these standards.
Mark Shaw, cabinet member for transportation said: “I would encourage all drivers to have regular eyesight checks to make sure they meet the legal requirements driving.
“Drivers with poor vision are a danger to themselves and other road users; if you can’t see very well, you might not see a hazard or person in time to react or stop. The general recommendation is to have an eyesight check at least every two years or straight away if you notice any problems.
“Having good eyesight is a basic requirement of safe driving. It may also help to reduce the number of people injured or killed on our roads.”
For more information and advice on driving eyesight rules visit www.gov.uk/driving-eyesight-rules