User blog comment:FairyRaven/Fairy Tail Chapter 428: When We Take Different Paths, Review and Commentary/@comment-7418318-20150419081221/@comment-7418318-20150419084755

There's that too. When the same thing happened to Erza during the Kyouka confrontation I thought it was due to her sense of sight being take away. Now I wonder if maybe those weird eyes were a way to visually expresse intense pain.

I wonder if Hiro made this parallel between Erza's and Lucy's torture to hint at Mary having similar abilites to Kyouka.