Eyes are the window to the soul—and in India, they're also the key to mastering Kathakali, a traditional emotive dance native to the state of Kerala.

Great Big Story took a tour of Kerala Kalamandalam University of Art and Culture where Kathakali is taught, and got a behind-the-scenes look at some of the students who spend nearly 12 years of their lives polishing choreography, which includes eye movement.

As Kalamandalam Ravi Kumar, a teacher at the university, told Great Big Story, the dance is based on Hindu legends and "synthesizes music, vocal performers, choreography, and hand and facial gestures to express these stories."

You can watch the full video below, which also includes a glimpse into the elaborate four-hour costume preparation.