Does Indra Go Blind?

Unlike obtaining the Rinnegan like his future reincarnation Indra didn't he used his eyes was so powerful he didn't go blind by using the mangekyo abilities or shown any sickness.

What happened to Indra Otsutsuki?

After Madara's death, Indra was reincarnated into Sasuke Uchiha. Sasuke succumbed to the Curse of Hatred after being hardened by his brother Itachi Uchiha and manipulated by Tobi, both during impressionable points in his life.

Why do Sharingan users go blind?

An original Mangekyo Sharingan puts a strain on the eye. The ocular muscles are placed under a constant strain due to the unique chakra the Mangekyo consumes. That strain causes the user to gradually go blind.