RT Book, Section A1 Yeung, Helen H. A1 Walton, David S. A2 Kline, Mark W. SR Print(0) ID 1182925965 T1 Visual Impairment in Childhood T2 Rudolph's Pediatrics, 23e YR 2018 FD 2018 PB McGraw-Hill Education PP New York, NY SN 9781259588594 LK accesspediatrics.mhmedical.com/content.aspx?aid=1182925965 RD 2024/04/20 AB Vision is an essential sensory input from infancy throughout childhood that allows for normal physical, cognitive, educational, and social development and for adult occupational training. Vision is present at birth at approximately a 20/200 level. Visual acuity develops rapidly during the first year, with normal acuity reached by 9 to 12 months of age. Blindness or visual impairment can be assessed in terms of the level of visual function and by scoring functional vision related to quality-of-life achievements. Assessment of visual acuity is the most often used parameter for estimating vision. The assessment of visual acuity in young children is imprecise; therefore, it is necessary to define ranges of visual loss. Also, test results may improve with advancing age and development. Visual function has been categorized into 5 levels of performance, ranging from normal to visually impaired (Table 574-1).