Which one? when?

A story (vaguely remembered) that I heard in my childhood - in my words - 

A mountaineer, during one of his ventures, fell in a valley where everybody blind.

This valley was totally cut off from rest of the civilisation as there was no way to reach to the rest of the world from this place. The people in the valley had a society and an organised way of living.

They couldn't believe the story of this person, Jack. And specially his conversations, about 'seeing', were difficult for them to follow. However, he was allowed to live with them.

Jack after trying hard to get out of that valley, finally accepted it as his life. He fell in love with the most beautiful girl there.

This marriage was an objection for people in the valley as Jack's eyes had some kind of deficiency in their view. Finally a condition for marriage was decided that Jack had to be treated by blind surgeons for his eye problems.

Jack agreed.

The day for the surgery came. He woke up. Saw the rising sun. The beautiful morning. Realized that this is the last time in his life he is seeing all this. The thought scared him. He started running.
He didn't see the day or night, thirst or tiredness, just kept running.

Finally he found a place to enter his original world he had fallen from.