Purpose-To provide normative pediatric visual acuity data using HOTV optotypes presented on the Electronic Visual Acuity Tester following the Amblyopia Treatment Study (ATS) protocol.Methods-Monocular testing was conducted on 384 healthy full-term children ranging from 3 to 10 years of age (mean, 5.4 years; SD = 1.8 years). A total of 373 children completed monocular testing of each eye. In addition, 23 adults (mean, 28.7 years; SD = 4.9 years) were tested for comparison. Both monocular visual acuity and interocular acuity differences were recorded.Results-Mean visual acuity improved by slightly more than one line (0.12 logMAR) from 3 years of age to adulthood, increasing from 0.08 logMAR to −0.04 logMAR (F 6,400 = 26.3, p < 2.0 × 10 −26 ). At all ages, mean interocular acuity difference was less than one line on a standard acuity chart (overall mean difference = 0.04 logMAR; SD = 0.06 logMAR).Conclusions-These results represent the first normative data reported for HOTV optotypes using the ATS protocol on the Electronic Visual Acuity Tester. These data may play an important role in clinical practice, screening, and clinical research.Accurate and reliable measurement of visual acuity in children is essential for the detection and management of pediatric eye disease. Visual acuity is also a desirable outcome measure for pediatric eye research. Yet, though the Early Treatment Diabetic Retinopathy Study (ETDRS) testing protocol is generally accepted as the gold standard of visual acuity measurement in adults, 1,2 there is no widely accepted, standardized visual acuity protocol for young children. To remedy this, the Pediatric Eye Disease Investigator Group (PEDIG) has recently developed the Electronic Visual Acuity (EVA) Tester, a computerized testing system that provides automated presentation of letter optotypes (HOTV or ETDRS). 3Corresponding author and address to which reprints should be sent: James R. Drover, PhD, Retina Foundation of the Southwest, 9900 N. Central Expressway, Suite 400, Dallas, TX, 75231, Telephone: (214) Fax: (214) 363-4538, e-mail: jdrover@retinafoundation.org. The study was conducted at The Retina Foundation of the SouthwestThe authors have no commercial interest.Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. The EVA testing system offers a number of features that make it particularly suitable for multiple-site, pediatric vision testing. Most importantly, it offers standardization of optotypes, luminance, and testing procedure across sites and requires limited tester training. 3,4 For pediatric use, it incorporates the Amblyopia Treatme...