The assessment of visual acuity in school children is done using eye charts. The most used inclinical practice are Snellen and Bailey Lovie. The way they evaluate vision in children doesnot differ much from the way it is done with adults. However, when selecting the test, cognitivedevelopment must be taken into account. Objective: To determine the correlation between theSnellen numbers test and Lea numbers test in children between four and seven years of age inBogota. Materials and methods: The sample was chosen for convenience. We evaluated 169 visuallyhealthy children (331 eyes), aged between four and seven years, in the schools of the Institutode Bienestar Familiar, Bogota Optometry Clinic schools, and University of La Salle, between Mayand August 2011. Visual acuity (av) was assessed with a Snellen numbers chart and Lea numberschart with a Bailley Lovie type design. A Spearman test was used to determine the correlationbetween the two charts. Results: Results of the Spearman correlation test found a correlation of0.462 between both tests - moderate but statistically significant. With the Mann-Whitney test asignificant difference between measurements with both av tests was found. Conclusions: Snellenand Lea tests are different and, therefore, not interchangeable.

The contrast sensitivity tests (cs) are a powerful toll for determining the vision capability. It isimportant to know the development of this function and have precise parameters for the earlydiagnosis of abnormalities. <em><strong>Objective:</strong></em> To determine normal values for sc with the FunctionalAcuity Contrast Test (fact) in children between four and seven years in the locality of Chapineroin Bogota. <em><strong>Materials and methods:</strong></em> An observational cross sectional study was performed with 280eyes. They were classified into two groups: Group 1, four to five years of age, and group 2, sixto seven years of age, valuing contrast with fact for the different spatial frequencies. <em><strong>Results:</strong></em> csvalues were determined with the average, interquartile range and the statistical test U from MannWhitney, which revealed no significant differences for any of the spatial frequencies. The normalrange found for frequency A were between six and seven; for frequency B, between five and seven;for frequency C, between five and seven; for the frequency D, between four and seven; and forthe frequency D, between five and seven. Comparing the ranges for both groups, there were nostatistically significant differences in most frequencies. <em><strong>Conclusions:</strong></em> The range and average foreach of the frequencies were within expected ranges for the test; it was observed that there weredifferences in the development of cs between groups A and B, with a wider amplitude for the oldest.