Not sure if Chariot actually needs glasses or is it just a part of her Ursula-sensei disguise. All I know is I was happy she stuck with her actual red hair at the end of the show.
At any rate, a cute and fun read!
Ursula does needs the glasses. I think it was Yoshinari who said it on AnimeExpo a few weeks ago. To be honest, I prefer Ursula with the glasses too. She looks cuter with them.