Background: There is currently insufficient evidence to recommend vision screening for children < 36months of age. This study assessed the effect of comprehensive vision screening, as well as the sensitivity of age-appropriate vision tests, at two years of age on habitual visual acuity at 4.5years of age. Methods: Children born at risk of neonatal hypoglycaemia (n=477) underwent vision assessment at 54±2months of age including measurement of monocular and binocular habitual visual acuity, assessment of binocularity and stereopsis. Of these children, 355 (74.4 per cent) had also received vision screening at two years of age (mean age=24±1months), while 122 were not screened. Results: Eighty (16.8 per cent) children were classified as having reduced vision at 4.5years of age, but the prevalence of reduced vision did not differ between children who had previously been screened at two years of age and those who had not (15.5 per cent versus 20.5 per cent, p=0.153). However, children with reduced vision at 4.5years of age were more likely to have had visual abnormalities requiring referral detected at two years of age (p=0.02). Visual acuity and mean spherical equivalent autorefraction measurements were also worse (higher values) in two-year-old children who were later classified with reduced habitual visual acuity (p=0.031 and p=0.001, respectively). Nevertheless, unaided binocular visual acuity, non-cycloplegic refractive error, and stereopsis at two years all showed poor sensitivity and specificity for predicting visual outcomes at 4.5years of age. Conclusion: Our findings do not support the adoption of early vision screening in children as current vision tests suitable for use with two-year-old children have poor sensitivity for predicting mild-moderate habitual vision impairment at 4.5years of age.