And here I was thinking that Rider had square pupils.

Why did she masquerade as Rin during a sex scene in Unlimited Blade Works?

Uh... Oh... oh, is that why she wears the, uh... oh... oh okay. Yeah, that makes sense now.

comment #40816
If you take a look at who Rider's identity is, it's cause she's Medusa and a Gorgon (a creature that can turn people to stone with sight)
And yeah if you did take it off it would look something like that ^^''

Congratulations, it's a gorgon. You are now a lawn gnome.

Well, at least you'll be able to talk to burrowing animals...