It isn't a big deal that Lee can see in his legendary skin. He always could see anyway
I know what you are thinking when you first see that Lee Sin can see again: http://i.imgur.com/isAnea9.gif?Noredirect
But I am here to tell you the truth. I am here to tell you Lee Sin could see the entire time!
http://i2.kym-cdn.com/photos/images/original/001/041/121/476.gif
Lee Sin has a weakness for the ladies, and mistakenly revealed his fallacy in the name of lust: http://i.imgur.com/kQMO2uH.jpg?Noredirect
He has also been known to use his eye sight against enemies, if he is convinced that he can kill them. After all, dead men tell no tales. http://st.elohell.net/public/chill/9add97d7cb5885e987d386ba3b36a2fd.jpg
Finally, the Lord of Lies himself simply couldn't let another get away with his shtick without permission, and revealed the truth: http://www.quickmeme.com/img/8a/8a6c8ad5e0a5b67b2b34c940d698f0c33810398015b9837ff77b6928e5618d57.jpg