It's frightening when a peg sticks out right at eye level.
ご質問ありがとうございます。
「目の高さ」はthe height of (my) eyesですが、eye levelが実際に使われている言葉です。「ちょうど」を普通にexactlyに訳していますが、rightも使えますね。
例文：I like your peg decoration, but it's frightening when a peg sticks out right at eye level.
ご参考になれば幸いです。
If I stood up and there was a peg at my eye level, it would be scary.
It would be kind of dangerous if there were a peg near my eye when I stood up.
この場合、次のように言うことができます。
ーIf I stood up and there was a peg at my eye level, it would be scary.
「立ち上がって、目の高さに釘があったら、怖いよね」
there was a peg at my eye level で「目の高さに釘がある」
ーIt would be kind of dangerous if there were a peg near my eye when I stood up.
「立った時に目の近くに釘があったら、ちょっと危ないよね」
there were a peg near my eye で「目の近くに釘がある」
ご参考まで！
アメリカ合衆国 
カナダ 
