Sketch offers evidence Van Gogh cut off nearly all his ear

Opening Friday at the museum in Amsterdam, the exhibition "On the Verge of Insanity," charts Vincent van Gogh's descent into mental illness, his notorious self-mutilation in the southern French town of Arles and, finally, his decision to take his own life.

According to two simple sketches, all that was left was a small flap of the lobe.

The museum says they show how painting became a lifeline for Van Gogh during his battles with mental illness.