A rare ocular disorder where a second set of retinas grow on the lower rear section of the cranium. The extra retinas are extremely unsightly and sensitive to light so a pair of sunglasses, worn backwards on the head, are required in order to go outside. Other symptoms include spiky frosted hair and button-up shirts.
Guy Fieri first developed Fieri's disease when he got his own show on Food Network.
I wrote my med school dissertation on Fieri's disease in the Congo.