The visual standards below are a brief summary and apply to holders of a Group 1 (motor car) license. Higher standards apply to Group 2 licences.
You must wear glasses or contact lenses every time you drive if you require them to meet the standards of vision for driving. In good light (with the aid of glasses or contact lenses if necessary), you must be able to correctly read a standard size (post 1st Sept 2001 font) motor registration number plate fixed to a parked motor vehicle and containing letters and figures from 20 metres. Also, using both eyes together, you must have visual acuity of at least decimal 0.5 (6/12), measured on a Snellen letter chart. Glare may cause some to fail the number plate requirement, despite having good visual acuity on a the letter chart.
Field of Vision
The minimum field of vision for safe driving is 120° from side to side (with at least 50° to each side of the centre “point of fixation”) and 20° both above and below the horizontal mid-line. This is measured by an Estermann binocular (both eyes open) visual field test. Small defects may be permitted within 20° of the centre.
You must cease driving if you have double vision.
Loss of Vision in one Eye
If you lose vision in one eye or need to cover one eye to drive, you must inform the DVLA. You may drive when you have adapted to the disability and the vision of the good eye meets the driving standard on its own. However, you must inform the DVLA of any problem affecting the sight of the remaining eye.
Individuals not meeting Group 1 licence requirements may qualify as “exceptional cases” if their visual defect has been static for at least 12 months, caused by an isolated event or non-progressive condition and who have no other eye condition that may affect vision progressively.