<p>An hypothesis was postulated stating a possible relationship between the degree of estimation-error, induced in perception of visual illusion as in the case of Muller-Lyer’s, and the depth cues produced by line convergency. In order to test this hypothesis, twenty children of both sexes were used with the original Muller-Lyer Illusion and three variations designed by the authors. The result obtained confirmed our hypothesis at the 0.05 level confidence with a lesser illusion being found in those plates where the contextual depth cues were modi­fied. Likewise, possible cultural differences were found between the individuals of each sex in the perception of the four plates. These results lead us to expect certain potential relationships between cognitive control principles and depth perception as well as variations in illusion degree among subjects from different countries.</p>