At the end of the episode when Doug takes the bandages off Carrie's eyes, you can see she has makeup on around them and is wearing lipstick. Earlier in the episode, she said she couldn't put on make-up when her vision was bad, but even if she could, it wouldn't have lasted that long.
Doug: (watching Woody Woodpecker) I still don't get it.
Doug: Hey, listen, since you're gonna be seeing clear from now on, I feel I should warn you... I'm a little overweight.
The German episode title is "Blinde Kuh", meaning "Blindwoman's Bluff".