In amblyopia diagnostic there is important to choose the visual chart to measure the visual acuity: morfoscopic or angular since due to the crowding phenomenon it turns out logical that it is easily to discriminate isolated characters than linear characters. <em><strong>Objective:</strong></em> to determination if there are significant difference between the visual acuity results measured up to the Snellen chart , Bailey Lovie chart and chart of isolated letters in patients with refractive amblyopia between 5 and 12 years. Materials and <em><strong>Methods:</strong></em> there was realized a comparative study of the results of visual acuity, measured up to three charts in far vision in 20 patients (40 eyes) by confirmed diagnosis of refractive amblyopia between 5 and 12 years, at the Unit of Pediatric Optometry and visual Training of the Optometric Research Institute of LaSalle University in the period between February and April, 2007. <em><strong>Results:</strong></em> the Pearson’s coefficient of correlation shows a higher correlation between the visual acuity taked with isolated letter chart and Snellen chart (0,7200407) and the lowest correlation between the Snellen and Bailey Lovie’s charts (0,6425297). In the variance analysis, there were significative differences between the values of visual acuity of each chart (p < 0.05). Dunnet’s test (isolated letter chart as control) shows that there was statistically significative difference between the results of Bailey’s chart and isolated letter chart (p < 0.05). There were not statistical differences the value of acute visual with Snellen VS isolated letter chart. Conclusions: There is a high correlation and there isn´t significative difference between isolated letter and Snellen chart, probably due to the fact that both of them use the same letters, which can lead to a high rate of memorization. There exists significative difference and low degree of correlation between visual acuity with Bailey Lovie’s chart and isolated letter chart. The difference between the angular and morphoscopic visual acuity is determinant at the moment of taking the visual acuity in order to diagnose the crowding phenomenon in this patients.

<em><strong>Objective</strong><em> to determine the reference values of visual acuity, refractive status, corneal curvature, stereopsis and color vision in children between the ages of three and seven in the locality of Chapinero in Bogota. <em><strong>Materials and methods</strong><em> cross-sectional descriptive observational study. The population under study consisted of schoolchildren between the ages of three and seven (200 children). Measurements included visual acuity (VA) with the Lea Symbols and HOTV tests, cycloplegic refraction, keratometry with Nidek KM-500 autokeratometer, color vision with Color Vision Testing Made Easy and stereopsis with Randot test. <em><strong>Results</strong><em> The median visual acuity in all age groups was 0.00 (20/20). One hundred percent of the children had hypermetropia (spherical equivalent for astigmats of up to 1.00 Dpt). The medium refractive error was + 0.75 in the groups of three and four-years-old, +0.50 in the groups of five and six-year-old children and +0.62 in the group of seven-year-old children. The median corneal curvature in the horizontal meridian was 42.62 and 41.50 for the vertical meridian of three and four years, 42.75 horizontal meridian and 43.75 the vertical of five and six years, and 41.50 and 42.50 at seven-years-old. All had normal color vision. The median stereopsis was twenty-five arc seconds for three and four-year-old children, twenty arc seconds for five and six-year-old children and twenty-five for the group of seven-year-old children.