A new study conducted at NASA’s Ames Research Centre in California identified a simple and easily obtainable set of eye movement measurements that can provide accurate insights into whether a person is sleep-deprived.
Participants spent two weeks on regular 8.5 hours per night sleep schedule and abstained from alcohol, drugs, and caffeine so that they were sure they started the experiment from the same baseline. Then participants spent up to 28 hours awake, where they were tested periodically to monitor how their visual and eye-movement performance changed.
The researchers found that when participants were asked to track stimuli with unpredictable onset, direction, speed and starting location, human eye movements were dramatically impaired.
These findings have important implications for people working in high-pressure jobs such as surgeons, military personnel, and truck drivers. These measures could be used to assess individuals working nightshifts.
Lee Stone, senior author on the study said: "There are significant safety ramifications for workers who may be performing tasks that require precise visual coordination of one's actions when sleep deprived or during night shifts. By looking at a wide variety of components of human eye movements, we could not only detect sleepiness but also distinguish it from other factors, such as alcohol use or brain injury, that we have previously shown cause subtly different deficits in eye movements."
Access the study in the Journal of Physiology here.