Vision screening in the under-5s.
D000367:Age Factors; D002648:Child; D002662:Child Health Services; D002675:Child, Preschool; D006801:Humans; D008131:London; D008403:Mass Screening; D009988:Orthoptics; D010043:Outcome and Process Assessment, Health Care; D014786:Vision Disorders / Q000175:diagnosis / Q000453:epidemiology*; D014787:Vision Tests / Q000379:methods; D014792:Visual Acuity