I was in the car today when I started thinking to myself, "Doesn't Z wear contacts?" Sure, it seems like a dumb question since she's just a doll and dolls can't put in contacts, but I got contacts last month, so the question came to me. Here's the reasoning to why I think Z wears contacts:
Here's a picture of Z with her glasses:
And Z without them:
If she can function normally without glasses, but wears them sometimes, I think Z wears contacts. I own Z's Accessories, which comes with her glasses, and they have lenses, so that makes it clear it's not just for show.
What do you think?