Jayantha, s/o of Indra came in the form of Kaakaasura, with the avesha of Kuranga. Kuranga was staying in the eye of Jayantha, the crow. Kuranga was blessed with the varaa As long as crows have two eyes, he will not die. Sriramachandra killed Kuranga with his arrow on one of the eye of the crow. That is why Crows cannot open both the eyes even today.