Then she dropped it on the floor of a dusty room while hiding from Purvi during the sangeet, yet next thing you know she'd successfully picked it up from the dusty floor and put it back in her eye, no need for rinsing with contact solution. And once again, magically, no irritation experienced.
And now suddenly, a little smoke in her eye and so much irritation?! I just don't get it :p
EDIT:
Interesting points were brought up in the comments!
It was argued that Tanveer felt irritation in her normal eye, not her stone eye. Because you can't feel anything in a stone eye. But I went to watch the episode again and I found this:

She's covering her left eye, which is her stone eye! Which means she felt irritation in it. See from an earlier episode, her stone eye is indeed the left eye:

So now it makes even less sense haha.
And then I realized that first of all, it doesn't even make sense for Tanveer to wear a lens in her stone eye at all, because contact lenses stick to your cornea. Tanveer's stone eye doesn't even have a cornea. How does it stay put at all?!
Okay I may be thinking about Tanveer's stone eye a little more than is healthy... :p
125