"While I was three I had an eye surgery."
Translation:Üç yaşındayken göz ameliyatı oldum.
As many have pointed out (you first, if I'm not mistaken) the English is incorrect.
And still not corrected.
And not reportable.
One of the curious features about Duolingo (or the part I know, which is the Turkish tree) is that various pieces of the Report function vanish according to some programming choices that would have been better omitted.
TLDR; Yes. But it's not an idiom.
Disclaimer: I'm not a native Turkish speaker
Etymologically, ameliyat is more close to the word "operation", as it can mean other things than a "surgical procedure" .
From my experience olmak, and etmek usually turn Arabic loanwords that are in noun form into things that "happen"... In English surgery is not a verb and it doesn't "happen" by writing "I eye surgeried". You have to write "I had" eye surgery to describe that it has happened. "oldum" takes the role of "I had" here.
For that reason, I don't think any of this is idiomatic.
I think you're right that it should not be called an idiom, yet I felt this use of 'olmak' idiomatic because it is supposed to mean 'to be, to become, to happen', so 'göz ameliyatı oldum' to me would literally read as 'I became an eye surgery'.
With my very limited Turkish knowledge I would think I should say 'ameliyatım oldu' or 'ameliyatım vardı', since it is the surgery that happened, and not me, but I think none of these is actually correct.
But now I wonder, are there more phrases like the one above, where something happens to the subject / someone experiences something, and it is expressed with 'olmak' as an auxiliary verb?
As of 23 February 2021, the English sentence still reads: "While I was three I had an eye surgery." This sounds foreign to a native speaker. It should read, "When I was three, I had eye surgery," or, "I had eye surgery when I was three." In general, we don't use "while" when stating the age someone was when a past even occurred, only "when." And while we do use an article when saying, "I had an operation (on my eye)," we don't use it when saying, "I had (eye) surgery."