Eye movements differentiate between love and lust, according to new study results. The study, conducted by the University of Chicago researchers, notes that eye patterns focus on a stranger’s face if the viewer perceives the person to be a potential romantic love partner.

The study researchers also indicated that when the viewer feels sexual desire, the gaze moves over the other person’s body. This automatic judgment may happen in just half a second, resulting in different gaze patterns.

Lead author Stephanie Cacioppo, director of the UChicago High-Performance Electrical Neuroimaging Laboratory, said in a statement, “Although little is currently known about the science of love at first sight or how people fall in love, these patterns of response provide the first clues regarding how automatic attentional processes, such as eye gaze, may differentiate feelings of love from feelings of desire toward strangers .”

The study, which involved male and female students from the University of Geneva, found that both male and female students gaze more at a person’s face, particularly when feeling romantic love, with gazes shifting from the face to the rest of the body.

Co-author John Cacioppo said, “By identifying eye patterns that are specific to love-related stimuli, the study may contribute to the development of a biomarker that differentiates feelings of romantic love versus sexual desire.”