At the Arctic Development Project Office, experts showed old sunglasses of Arctic inhabitants – these are Nganasan glasses, that’s about reports NIA-Zapolyarye news portal.
They used narrow slits for the eyes instead of glass. Arctic residents used them only for a few months a year, in the spring, when the sun begins to warm more strongly and the snow shines and sparkles stronger due to the refraction of the rays. It was unsafe to remain in open areas for long periods of time without eye protection under these conditions. Eyes can become inflamed due to too much light and glare.
Cups are traditionally made from wood (especially spruce), bone, walrus tusk, reindeer antler, and sometimes coastal plants. The workpiece is cut to the face of the future owner, one or several narrow horizontal slits are made in front of it. Safety glasses fit tightly to the face, allowing light to pass through only through the slits, and carbon black is sometimes applied to the inside to reduce glare. The slits are narrowed not only to reduce the amount of incoming light but also to increase visual acuity. The wider the slots, the wider the field of view.
Previous scientists nominated Cosmic theory about the complete freezing of the Earth 700 million years ago.