Medusa was originally a beautiful maiden, but when she was raped, or seduced, by Poseidon in Athena's temple, the enraged virgin goddess transformed her beautiful hair to serpents and made her face so terrible to behold that the mere sight of it would turn a man to stone.
In a 1986 article for Women of Power magazine called "Ancient Gorgons: A Face for Contemporary Women's Rage," Emily Erwin Culpepper wrote that "The Amazon Gorgon face is female fury personified. The Gorgon/Medusa image has been rapidly adopted by large numbers of feminists who recognize her as one face of our own rage."
In a nihilistic interpretation of Medusa, attempts to avoid looking into her eyes represent avoiding the ostensibly depressing reality that the universe is meaningless.
ph: bernini, via flickr