Executive functions are cognitive processes that critically involve the frontal lobes and enable us to accomplish goals and make decisions in everyday life. The brain regions responsible for some executive functions (spatial attention and memory) overlap with brain regions necessary for eye movements. Eye movements can be more reflexive (automatic) or more voluntary (willful). Voluntary eye movements, especially, have become an important tool with which to measure different aspects of executive functions in many human disorders. They also have been critical in differentiating subtypes and evaluating medication or treatment efficacy in clinical populations.