I know that in Greece it was seen in bad light, but actually Plato's and Aristotle's views of eugenics were extreme, that in the end it was a father who had the will to expose the child on the woods or to rear it. However ableism was surely the common norm even if recognizing the right to live, and I don't know anything about the rest of ancient cultures.
Not to discourage any further answers, but you'll probably like these older answers from the FAQ:
What happened to Spartans who could not fight due to injuries?
What happened to Spartans born with congenital defects?
Both by /u/Iphikrates
You are a Roman soldier on the march, your leg breaks for whatever reason. What happens to you next?
What was life like after being wounded in the Roman military?
Both by /u/Celebreth