The eyes, it is said, are the windows to the soul. But new research suggests they may also offer clues that can predict the development of depression.

According to a new study out of Binghamton University, how much a child's pupil dilates in response to seeing an emotional image can predict his or her risk of suffering from depression.

Lead researcher Brandon Gibb, professor of psychology at Binghamton University and director of the Mood Disorders Institute and Center for Affective Science, said the new findings suggest that such physiological reactions could sever as a quick and inexpensive biomarker for the mental health disorder.

"We think this line of research could eventually lead to universal screenings in pediatricians' offices to assess future depression risk in kids," said Gibb.

His findings are based on a study of children whose mothers had a history of major depressive disorder. Gibb’s team measured the children’s pupil dilation as they viewed angry, happy, and sad faces.

Follow-up assessments over the next two years showed that children with greater pupil dilation to sad faces experienced higher levels of depression.