Albert Einstein - The company that his father and his uncle had built was sold to buyer because they could not keep the company. The lost to a bid which was the only sure way to keep the company running. The family transferred to Italy to look for another business. Einstein remained studious and dedicatedThomas Edison - He had hearing problems when he was a child but that did not stop him from creating his inventions.
The freed prisoner represents those who understand that the physical world is only a shadow of the truth, and the sun that is glaring the eyes of the prisoners represents the higher truth of ideas.
I think it would be an idiom or allusion. More towards an idiom though.
