Lying requires a long‐term memory search and is a cognitive load task. Telling a spontaneous lie is associated with a higher cognitive load compared with the truth, although when memories are planned before telling a lie, the cognitive load can be less compared with the truth; therefore, telling a spontaneous lie could be associated with a higher cognitive load compared with a planned lie. In this study, we examined cognitive load, as measured through oculometrics, to identify deceit in interviews. Twenty‐four subjects were questioned, and their answers classified as spontaneous lies, planned lies, and truths. Results show that saccades and fixations were associated with a higher cognitive load when telling spontaneous lies compared with telling truths. Blinks and pupillometry show that subjects require greater cognitive load when telling truths compared with planned lies. Finally, telling spontaneous lies required higher cognitive load compared with planned lies, as assessed by blinks.