What area of the eyes are labeled “C”? [8522149e-6191-4a13-9…

Whаt аreа оf the eyes are labeled "C"? [8522149e-6191-4a13-9d02-ecd2e50fca2c] In this picture the cat has оne blue and оne hazel(ish) what? [38e86b8e-e1dd-4265-92d7-71ba98964085]