pretty telling that first reation of some here can be summed with: what is really white?
I assume people with medium lightness would be categorized contextually by them, sort of like how people with skin tones that don't read clearly black or white are irl. If someone with ambiguous eyes is wearing a hand sleeve and acting noble you'll assume she's a light eyes, but if she's wearing a glove and interacting with laborers you'll assume she's a dark eyes.