I don't think so, in this simplistic artstyle with their eyes being completely in shadow of their leaf-hats it would probably look weird to try to make 'shadow-y eyes', instead not showing them at all like the shadow is too much to make out their eyes anyway. Also, they are shady-mysterious (living hidden in swamps) side chars, their faces don't really matter, no eyes puts emphasis on that.I assume the swamp ladies without eyes is a bug right?
Thats my understanding at least.