Siva and Parvati were enjoying a very pleasant day at Mandara parvat. Parvati closed the eyes of Siva playfully and darkness descended on the universe.As she removed her hands from the eyes of Siva, the universe emerged out of darkness. Yet, from the droplets of sweat of Siva that fell on ground, a child was born and he was blind.
As soon as he was born he cried and laughed. He is very ugly in looks.
Parvati removed her hands and universe got rid of darkness.
Siva asked Parvati with a smile." You are the one who closed my eyes and caused darkness.Why do you look terrified now?"
Parvati replied with hesitation." I see this ugly being before my eyes roaring fiercely. Who is this?
Siva said " Uma..he is our son born from my sweat caused by your touch. He is born blind because he got life when you closed my eyes. He will be called Anthak. Be merciful and save him from ganas since he evokes terror."
Parvati nodded her head and nourished him with the help of her maids . Within a short period Hiranyaksha did penance seeking a son for him.Andhakasura grew up to be a competent warrior, faced jealousy in the palace from his siblings and did rigorous tapas to earn attention of Lord Brahma. When Brahma appeared he asked for a life of victories . And a life without death. The second part was not granted. Andhakasura then requested he should die when he would try to grab the unattainable If he desires a mother like woman that should lead to his last moment.So that was the boon given by Brahma.
Vishnu , who vanquished Andhaka's foster father Hiranyaksha asked the Devas to wait for an opportunity to see the downfall of Anthaka.,who is invincible to him even.
Devi Yogeswari joined the Matrikas created by the warring seven gods. Each of these Matrikas was identically endowed as the god she was representing.
Yogeswari and the Matrikas started to drink each droplet of blood of Andhakasura, thus stopping him from multiplying
Gradually, Andhakasura was cornered. He could not multiply further and his strength started getting depleted.Siva , then, struck his final blow. He pierced Andhakasura's chest with his trident and held him up. After a thousand years' in the suspended position, Andhakasura realised his mistake and prayed for forgiveness. After his death he wanted to be with Siva and serve him with whole hearted devotion.
Siva blessed him to lead a reformed life among the Pramathas and Ganas.
Source: Siv Maha Puran Yuddha Khanda Rudra Samhita