The legal requirement for Group 1 drivers ( non-commercial) requires the ability to identify the letters on a number plate at 20.5metres (67 feet).
This corresponds to a binocular visual acuity of approximately 6/10 on the Snellen chart.
As well as the statutory number plate test, the DVLA recognise that an adequate field of vision is necessary for driving. The Royal College of Ophthalmologists in its advice to the DVLA has defined;
“the minimum visual field for safe driving is a field of vision of at least 120° on the horizontal meridian. In addition there should be no significant field defect in the binocular field which encroaches within 20° of fixation either above or below the horizontal meridian.”
Our distance vision often deteriorates either in our 20s ( due to myopia) or 50s.
If you find yorself squinting to look at roadsigns or numberplates, book an appointment to have your eyes checked immediately.