He doesn't seem to care about other people's opinions at all.
そんな小さな問題は眼中に入らない。
Such a trivial matter is not worth paying attention to.
within the eye
Original literal meaning; now rare and mostly found in classical or explanatory contexts.
「眼中」は文字通りには目の内側を指すが、現代ではほぼ使われない。
Literally, 眼中 refers to the inside of the eye, but it is hardly used that way in modern Japanese.
out of consideration; not an option
Compound of 眼 (eye) and 中 (inside). The figurative sense of 'within one's consideration' developed from the literal 'within the eye'.