How did people handle crushing sunlight? Did they just shade their eyes with a hat?
I know glasses existed, but was it effective to tint them, or is this a recent combination of ideas?
I don't have my anthropology textbook at hand so I don't have a source to give, but google 'Inuit sunglasses'. Bone goggles with a narrow slit.
I'd love to hear if there's any scholarship on this invention, but you'd have to think they were invented in prehistory.