Q919: What are the eyesight requirements to drive?
- Distance – the legal requirement is that you must be able to read in good daylight, with the aid of corrective lenses if worn, a motor vehicle number plate of the prescribed size at a distance of 20.0 metres or 12 metres for category K vehicles (mowing machines or pedestrian-controlled vehicles). The prescribed size is letters 79 mm high and 50 mm wide. You must also not have been told by a doctor or optician that your eyesight is currently worse than 6/12 (decimal 0.5) on the Snellen scale, using both eyes or one eye if you have sight in one eye only - you may use glasses or contact lenses. If there is any doubt about this you should speak to your doctor or optician.
- Field of vision - this must also be of a satisfactory standard, your optician can explain about this and carry out a test.
- Distance – if you drive a lorry or bus you must have a visual acuity of at least 0.8 (6/7.5) measured on the Snellen scale in your best eye and at least 0.1 (6/60) on the Snellen scale in the other eye. This standard can be achieved using glasses with a corrective power not more than (+) 8 dioptres or contact lenses. There's no specific limit for the corrective power of contact lenses.
- Field of vision – you must have a horizontal visual field of at least 160 degrees, the extension should be at least 70 degrees left and right and 30 degrees up and down. No defects should be present within a radius of the central 30 degrees.