Medical advisers at the Driving and Vehicle Licensing Agency have acknowledged that the number plate test is inaccurate but the government is standing by its proposals to retain the test and make it easier.
Last week the DVLA launched further consultation on eyesight standards for drivers and said that the original consultation document, published in February, 'did not accurately reflect some of the opinions of the Medical Advisory Panel on driving and visual disorders'.
In documents released with the new consultation, the panel said it recognised that the number plate test 'is not an accurate method of assessing [visual] acuity' as defined by the EU Directives on driving licences but considered that a number plate test could be used as a screening test.
'In the event of an individual failing this then evidence of having a VA of decimal 0.5 (Snellen 6/12) would be acceptable,' the panel said. It advised that 0.5 acuity could be measured clinically using either a LogMar chart or the 6/12 line on the Snellen chart.
The documents also reveal that the panel favours the number plate test used for screening to be the same as the current test, taken at a distance of 20m. Despite this recommendation, the government is still proposing to make the test easier by reducing the viewing distance to 17.5m.