A stroke can impact on an individuals vision in a variety of ways including
Visual Field Loss – this reduction in the field of view may impact on the ability to hold a driving licence and the licensing requirements for the country must be consulted. In the UK the current standard visual field requirement for a group 1 licence in 2022 is
“A field of at least 120° on the horizontal measured using a target equivalent to the white Goldmann III4e settings.
The extension should be at least 50° left and right. In addition, there should be no significant defect in the binocular field that encroaches within 20° of the fixation above or below the horizontal meridian.”
A stroke can cause a variety of changes in the area that a person can see depending upon the area of the brain damaged. This can include hemianopia (hyperlink to page) and quadrantinopia (hyperlink to page)
If an individual does not meet the visual field standard then there may be an opportunity to have their driving assesses under “Exceptional case” rules (hyperlink to Exceptional cases)
Eye movement disorders leading to double vision ( DIPLOPIA)
After a stroke the muscles controlling eye movement can be affected, resulting is failure of eyes to move together (disconjugate eye movements) resulting in double vision.
Diplopia (double vision ) usually results in revocation of a driving licence unless it can be controlled. It can be controlled by patching the effected eye (noting the person still needs to meet acuity and visual field standards with remaining monocular vision), a prism within spectacle lenses offered by an orthoptist or opthalmologist, regular botulinum toxin injections to prevent eye muscle spasm causing diplopia undertaken by an ophthalmologist or even surgery . Licensing Authorities usually require specialist advice that diplopia has been controlled before considering relicensing.
Visual neglect/inattention (hyperlink to visuospatial recognition section in visuspatial skills)
This is not a visual difficulty, but an impairment of attention as a consequence of brain damage, usually seen after a right hemispheric stroke. Individuals fail to notice objects or activity in one field of vision (usually left) so they bump into them. In the UK this prevents the holding of a driving licence, and local driving legislation must be consulted if this is identified.
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