He told PTI that he had an eye transplant years ago and opened up about it during a chat show, a video of which has gone viral now.
"There was this kid on the show whose mother had lost vision because of some tumour. I spoke about my vision problem to motivate them and tell them that life goes on. I said it a long time ago and I never knew it will break out now," says Rana.
The actor, 32, says he does not even consider it a problem.
Rana essays the role of antagonist Bhallala Deva in "Baahubali: The Conclusion", which hit the screens last week.
More From This Section
The film has some of the grandest war scenes ever seen on Indian celluloid and Rana says they would often joke about him missing the target while filming these sequences.
"On most of my sets, it is a joke. Like Prabhas would always ask whether I could see the mark before the beginning of an action sequence," he says.
Rana says if the content is good nothing can stop a film from making history.
"I am really happy with the appreciation 'Baahubali' is receiving. Its success proves that if you back the right content, it can travel across the country and the globe.
"'Baahubali' team is not after numbers. If we would have been number guys, we would have never made a film with such a huge budget. We just wanted to make the biggest war film of this country but what it has achieved is amazing," he says.