Zhang X, Zhou M, Ma X, et al. - In this cluster-randomized clinical trial, researchers estimated the impact of providing free spectacles on uncorrected visual acuity (VA) among urban migrant Chinese school children. After baseline survey and VA screening, eligible children were randomized by the school to obtain one of the two interventions: free glasses and a teacher incentive (tablet computer if ≥ 80% of children given glasses were wearing them on un-announced examination) (treatment group) or glasses prescription and letter to parents (control group). Of the 4,376 children randomly chosen, 728 failed VA screening and met eligibility requirements at 94 schools. There was no evidence indicated that spectacles wear worsens children’s uncorrected VA among urban migrant Chinese school children.