<p>The purpose of childhood vision screening is the early detection and treatment of ophthalmic disorders and surveillance for visual defects throughout childhood. Unlike other screening programmes which aim to identify a single disease entity, the objective of vision screening is to search for a range of visual problems. There is little information about the effectiveness of screening for abnormalities in childhood even though there are obvious difficulties in measuring and interpreting children’s visual function. Most, although by no means all, health districts have provided vision screening for school children for over 20 years.</p>