Frequency-doubling Technology IFDT) Perimetry was introduced as a rapid, easy method for detection of visual-field defects in adults. Its reliability, howev, has never been tested among pediatric patients. The purpose of this study was to determine if children could complete a screening program of FDT Perimetry reliably and to define the age range over which it might be most applicable.Two hundred fifty-nine normal children (mean age, 10.7 years; range, 4 to 17 years) were asked to complete the FDT C-20-1 screening test as part of their general eye examination. The visual-field results were analyzed for reliability using the number of false-positive errors, fixation losses, and visual-field defects. For the purposes of this analysis, field results were considered unreliable with false-positives > or = 1 or fixation errors > or = 1. The visual-field test was also considered unreliable if > 2 sectors were flagged.Data from 254 children were included in the analysis. Five children were excluded because of suspected malingering or ocular health diagnosis that may have produced a visual-field defect. False-positives were less than one for all but the youngest age group 14 years old). Fixation errors decreed with increasing age and fell below one (became reliable) at approximately 9 years of age, and remained less than one through 17 year. Visual-field loss for purposes of this study when present in more than two sectors was considered unreliable in this normal population.Children ages 10 years of age and older can reliably complete the FDT C-20-1 screening field test using the strictest criteria, combining false-positives, fixation losses, and visual-field losses. These data are derived from normal subjects, who on complete eye examination, had no ocular disease or reason to suspect visual-field defects.