Data are presented on the distribution of binocular visual acuity for 1368 drivers at 25 sites using a british standard test chart rather than a vision screening device. Assuming that the department of transport number plate test is equivalent to an acuity standard of between 6/12 and 6/9, it is estimated that between 1 per cent and 3 per cent of all drivers would fail the test at any given moment. Acuity was found to decline with age for drivers aged over 40 years. Five per cent and 10 per cent respectively of drivers aged 65 or over failed to meet the criteria of 6/12 and 6/9. A quarter of all drivers tested were actually wearing spectacles or contact lenses prior to driving up to the testing station; only 15 (4 per cent) of these drivers were wearing contact lenses. Questionnaire responses indicated that 64 per cent of all drivers claimed to have had some form of eye test within the previous 3 years. The effects on drivers' acuity of type and use of optical prescription, and of length of time since last eye examination, are reported.
Samenvatting