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;
If you are a commercial driver your requirement may be different. Details can be found at the DVLA ‘Changes to vision standards’ website page
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.