To look someone in the eye 双眼直视某人
The cornea is the transparent front part of the eye. Corneas can be transplanted by an operation where a damaged or diseased cornea is replaced with one from someone who has just died. The first cornea transplant was in 1905 by Eduard Zirm. It was one of the first successful transplant operations.
To look someone in the eye 这个短语的意思就是你双眼直视对方，让对方相信你所说的话是完全真实的，即使你有可能并没有说实话。
John looked me in the eye and told me that he loved me.
I looked at my boss in the eye and told him exactly what I thought.
如果英语里碰到 more to something than meets the eye 这个形容方式，意思一般是“某事/某物其实另有文章”。
I don't like Jane's new husband. He seems kind and gentle but I think there's more to him than meets the eye.