Hand-eye coordination is important in all aspects of life, from feeding to high-level sports. Individuals who possess the ability to process a greater amount of visual information in a shorter period of time may have a competitive advantage over slower counterparts (6,7), especially in regard to athletes. Quickly processing information and reacting appropriately is also paramount in day-to-day activities necessary for survival, and functionally can be a window into a subject’s overall cognitive status (6-8).

The ability to react to a stimulus requires a vast and complex network of processing and integration involving visual cues (occipital lobes), motor planning (frontal lobes), spatial orientation (posterior parietal cortex), and balance and coordination (vestibular system/cerebellum) (3-6). Once processed and responded to, a person’s response is recorded by the D2 as a reaction time.

Reaction times, accuracy and speed of movements can be assessed both when the subject is playing and when a definitive reaction time has been generated. Because of the vast connections and integration involved in the processing of this information, any abnormalities found may be correlated to a subclinical area along the neuronal-axis that may be causing issues related, but not limited to, cognitive deficits, balance issues, visual limitations, degenerative conditions such as, Alzheimer’s Disease (9) and Parkinson’s Disease (10), and even psychological conditions such as Schizophrenia (11,12).

Although this type of training has been traditionally used for the rehabilitation of athletes and individuals seeking performance optimization, its use is not limited to just that. Due to the above implications in the same areas of the brain, the D2 has also become a standard device used in neurorehabilitation, stroke recovery, and concussion evaluation and rehabilitation (2-12). As a matter of fact, individuals do not even need to be able to voluntarily perform the task. We have observed and are in the process of researching passive hand-eye coordination to illuminated targets in toddlers, individuals with paralysis, neglect syndromes, and even altered states of consciousness!