expression, suru verb (irregular)
open one's eyes wide; stare intently
Idiomatic expression describing someone straining to see something, often when searching or scrutinizing. Literally 'make one's eyes into plates'.
彼は目を皿にして間違いを探した。
He opened his eyes wide and searched for mistakes.
目を皿にして探しても、鍵は見つからなかった。
Even though I looked with eyes wide open, I couldn't find the key.