“KARMA”
Yes, Karma of Dhritarashtra led him to lose all his son. I have read two stories about it both are almost similar.
After losing all his sons in a war Dhritrastra bowed down before Lord Krishna and prayed. “Oh, Lord! There cannot be anyone in this world who is as unfortunate as me. I was born blind, I never saw my children’s faces and I don’t know how they looked like. I never did anything wrong in my life, I was limited by blindness. Why did I still have to go through this terrible punishment? What wrong did I do?”
Then Lord Krishna explained the law of karma to Dhritarashtra, He said,” Rajan, There are three types of Karma-
— Kriyamana Karma
— Sanchita Karma
— Prarabdha Karma
Kriyamana Karma is what we do in everyday life and the result we face in a few days. Rest two karmas are related to each other, They stay and get accumulated. Prarabdha Karma is part of sanchit karma that means a collection of past lives karma.
After describing the karmas Lord Krishana gives a divine vision to him to see his past 50 births. Dhritrashtra discovered that 50 births back he was a ruthless hunter and once just to have some fun he threw a burning net on a tree full of birds. Thus causing 100 young birds to be burnt to death. While the remaining birds managed to escape, they became blind due to the scorching heat caused by this fire.
Due to the effect of Sanchita Karma, he was destined to remain blind in this Life and also lose his 100 sons.
After listening to Krishna’s enlightening explanation, Dhritrashtra inquired “Krishna why did I not get punished in that birth itself, or the next birth, for the great sin that I had committed? Why now?”
Lord Krishna smiled and said,” Your Karma had to wait for an opportune time for 50 Births. During which time you could earn and accumulate enough pious deeds to attain the merit of being born a king and have 100 sons in one lifetime. The Sanchita Karma accumulated over the last 50 births would influence your life as Prarabdha Karma and could then instantaneously confront you with the effects of that evil action.”
According to the second story, Dhrtrastra was a hunter in one of his previous birth. One day when he was trying to kill a bird, the bird flew away. He tried so many times to kill it but every time it escaped. So just to seek revenge he climbed the tree and broke the nest of that bird. There were a hundred eggs in it. After this, he took more births as a tapas and did many pious things so he can get a hundred son in one of his birth. This is the reason he born blind and never saw his children as the bird never did.
Whichever version of the story is right the important thing is that-
Karma is the divine law of cause & effect by which every thought, word & deed justly return to us in this or future life. We learn to be compassionate, knowing that each experience, good or bad, is the self-created reward of prior expressions of free will.