strain one's eyes和strain one's eye 那个对?

strain one's eyes和strain one's eye 那个对? strain one's eyes catch one‘s eye还是catch one‘s eyes 求Napoleon’s life was one of strain and stress from his cradl strain keep one's eye on keep one's eyes on keep an eye on的区别 take one's eye catch one’s eye与catch one’s eyes都可以吗? hold[one's] eyes fix one's eyes 到底是the apple of one's eyes还是the apple of one's eye?也就是说eye到底 catch one's eye 放句子中eye还是eyes