This is me trying to portray depth/3D in a 2D image.
It should be fairly obvious why Diarmuid wears those sunglasses all the time. He’s not an albino – in fact, his eyesight’s fine – but just about everyone finds his eyes creepy in-universe (and quite a few in meatspace as well). Siobhán doesn’t any more.
And here’s a timelapse recording of myself filling this in: