Snellen Visual Acuity Interpretation
Interprets Snellen chart visual acuity measurements. Standard notation: 6/x metres (UK) or 20/x feet (US). Used to screen for visual impairment, assess driving eligibility, and guide referral to ophthalmology.
Score interpretation
VA 6/6 or better — normal vision
→ Routine review; no intervention needed; encourage regular optometry review (every 2 years); driving standard met
VA 6/9 to 6/18 — mild to moderate visual impairment
→ Referral to optometrist; update spectacle/contact lens prescription; if uncorrected, check with correction; if best corrected VA 6/12 or worse, note driving restrictions (DVLA standard 6/12 binocular); check for cataract, refractive error, macular disease
VA 6/24 or worse — significant visual impairment; below driving standard
→ Urgent ophthalmology referral; assess for treatable causes (cataract, glaucoma, ARMD, diabetic retinopathy); if VA <6/60, register as severely sight impaired (blind); DVLA notification required if VA <6/12 binocular; low vision aids; social services referral; RNIB signposting
Interpretation bands for the Snellen Visual Acuity. Apply clinical judgement and local guidance.
References
- Snellen H. Probebuchstaben zur Bestimmung der Sehschärfe. Utrecht: Van de Weijer, 1862.
- DVLA. Assessing fitness to drive: a guide for medical professionals. UK Driver and Vehicle Licensing Agency. 2023.
Related
Curated clinical cross-links plus same-class fallbacks.
- Adult Upper Airway Obstruction (Stridor) · DAS 2015 unanticipated difficult airway; RCEM
- Epistaxis Management · ENT-UK / NICE
- Acute Otitis Media · NICE NG91 2018
- Tonsillitis and Sore Throat · NICE NG84 2018
- Benign Paroxysmal Positional Vertigo · NICE CG124 / AAO-HNS Guidelines
- Acute Rhinosinusitis · NICE NG79 2017 / EPOS 2020
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.