The maturation of linear acuity and compliance with the Sonksen-Silver Acuity System in young children.

The compliance and maturation of visual acuity of 1245 2 1/2- to nine-year-olds was investigated. Testing was undertaken as part of routine surveillance. Ability to letter match, to achieve a binocular measure and to achieve monocular measures for children under three years was 89, 78 and 37 per cent, for children aged three to four years 97, 91 and 66 per cent, and for children over four years 99.9, 99.9 and 99, respectively. A statistical model was developed to give acuity norms by age for use by surveillance and diagnostic teams.