Chapter 7
Minerva McGonagall always saved the eyes for last. They might start with the eyebrows on the tremendously difficult subject of unsaid human transformations, but there was little you could not repair when it came to that area. The eyes, however, were the most difficult to get right, as well as the most disastrous when gotten wrong. She had no desire to see any of her students permanently lose their eyesight in the penultimate year of their education, or lose both eyes entirely in one lesson gone wrong. She cautioned her students, severely so. Safety was paramount, after all.
Apart from that however, she had found out years ago that one could gain a surprising amount of information about the students just in the moment they thought they were turning into someone else. Their inner selves revealed as outer appearances changed, so to speak, all defenses crumbling as they were no longer perceived as necessary...
It was foolish, of course, but oh so entertaining.
...Not that she got much entertainment from Mr. Weasley, whose eyes were still stubbornly stuck in their own colour. She fought back the smile that was invading her lips as she recalled the Weasley twins, vehemently assuring her that they had mastered the spell and switched eye colours. She moved on to Mr. Potter, who displayed one eye in his mother's green and the other one in a light grey that oddly enough reminded her of Mr. Malfoy... before Minerva turned her attention to Hermione Granger, her heart skipping a beat as their eyes met.
Looking down at her student, Minerva could clearly see that both of the girl's eyes had turned the exact same shade of green she would see when looking in the mirror.