The dataset provides data on cognitive and temperamental determinants of the Müller-Lyer illusion recorded in a group of 170 participants aged 20-33. The cognitive predictors included: the field dependent-independent cognitive style and the efficacy of attention networks: alerting, orienting, and executive control. The temperamental indicators were searched in the context of the Strelau’s Regulative Theory of Temperament. The results confirmed that susceptibility to the M-L illusion is associated with field dependence. Rhythmicity as a temperament trait moderated the relationship between susceptibility to the Müller-Lyer illusion and the efficacy of alerting. At a low level of Rhythmicity, a relationship between lower efficacy of the alerting network and higher susceptibility to the illusion was observed. The revised version of the database contains raw data from all 15 trials of estimating line length in the illusory figure in Visual Illusion Simulation Task and all cue conditions in Attention Network Test.