双眼 (shuāngyǎn) means "both eyes" and is a slightly literary or formal way to refer to one's eyes. It is often paired with verbs like 睁开 (to open) or 闭上 (to close) in descriptive or narrative writing.
她用双眼紧紧盯着屏幕上的数字。
Tā yòng shuāngyǎn jǐnjǐn dīngzhe píngmù shàng de shùzì.
She stared intently at the numbers on the screen with both eyes.
他的双眼充满了期待。
Tā de shuāngyǎn chōngmǎnle qīdài.
His eyes were full of anticipation.
闭上双眼,你能听到风的声音。
Bì shàng shuāngyǎn, nǐ néng tīngdào fēng de shēngyīn.
Close your eyes, and you can hear the sound of the wind.