1) 用于解剖学意义时，依情况用单复数。

• He has blue eyes.他眼睛蓝色。
• Close the right eye.闭上右眼。

用于表示“视力”、“视觉”、“注视”时，依抽象的程度，用复数或单数。

• I couldn't believe my eyes when I saw her.我看见她时简直不能相信自己的眼睛。
• It happened before her very eyes.那是就在她眼前发生的。
• The carpet caught my eye.地毯引起了我的注意。
• I tried to catch his eye.我设法要引起他注意。
• Everything was under the watchful eye/eyes of the teacher.一切都在老师的严密注视下。
• Keep an eye on those two guys.留神那两个人。
• They turned a blind eye on what he was doing.他们对他的所作所为熟视无睹。
• Reading with an expert eye, she made minor changes.她用驾轻就熟的眼光浏览一遍，做出一些小修小改。

2) dark eye, black eye, green-eyed 分别见各条目。