To open one's eyes (physically), raising the eyelids to see.
朝、目を開くとカーテンの隙間から光が差していた。
When I opened my eyes in the morning, light was streaming through the gap in the curtains.
赤ん坊が泣き止んで目を開くと、母親はほっとした。
When the baby stopped crying and opened his eyes, the mother felt relieved.
手術の後で初めて目を開いたとき、彼は周りの景色を見て驚いた。
When he opened his eyes for the first time after the surgery, he was surprised to see his surroundings.
To open one's eyes (idiomatically): to become aware of the truth or a new way of thinking; to be awakened or to have one's eyes opened.
留学して初めて目を開いた。世界には様々な価値観があると知った。
Studying abroad opened my eyes for the first time. I learned that there are many different values in the world.
彼の話を聞いて、私は自分の偏見に気づき目を開かされた。
After listening to him, I became aware of my own prejudices and had my eyes opened.
新しい技術に触れることで、会社全体の考え方が目を開かれることになった。
Exposure to new technology caused the company's whole way of thinking to be opened up.