Our eyes is one of the important sense which helps to see but according to research it could also serve as a window to how stressed. Researchers has found that pupil dilation can be used to indicate the mental workload of a person when they multitask.

Previous studies on workload and productivity include physical aspects, such as how much a person walks or carries, but they do not take into account a person's state of mind.

Jung Hyup Kim, an assistant professor at the University of Missouri-Columbia in the US said "If your vitals are bad, then something is wrong with your body and doctors will work to figure out what's wrong with you.” He further added that  "Many people multitask, but currently there is no measurement for someone's mental well-being. However, we found that the size of a pupil could be the key to measuring someone's mental state while they multitask.”

Researchers compared data from a workload metric developed by NASA for its astronauts with their observations of pupillary response from participants in a lab study. Using a simulated oil and gas refinery plant control room, researchers watched as the participants reacted to unexpected changes, such as alarms, while simultaneously watching the performance of gauges on two monitors

In the research Researchers discovered that pupil dilation could be used to indicate the mental workload of a person in a multitasking environment.