Piyasena P, Olvera-Herrera VO, Chan VF, et al. - According to this systematic review and meta-analysis, a positive association was found between vision impairment and traffic crashes in low-income and middle-income countries (LMICs). The findings justify the requirement of a vision function test before issuing a driver's licence.

• The authors discovered 49 (1·8%) eligible articles of 2,653 examined and incorporated 29 (59·2%) in the various data syntheses.

• The sample consisted of 15,394 candidates (mean sample size n = 530 [SD 824]; mean age of 39·3 years [SD 9·65]; 1167 [7·6%] of 15,279 female).

• The prevalence of vision impairment among road users ranged from 1·2% to 26·4% (26 studies), with colour vision defects ranging from 0·5% to 17·1% (15 studies), and visual field defects ranging from 2·0% to 37·3% (ten studies).

• A substantial proportion (range 10·6–85·4%) obtained licences without undergoing obligatory vision testing.

• The meta-analysis found that people with central acuity visual impairment had a 46% higher risk of being involved in a traffic accident, while those with impairments in colour vision or the visual field had an even higher risk.