Therefore, glasses on and there you go ...
Short for glasses (you can see it in the pictures not):
Lenses (plastic) have a blue tint - not colorless!
The brackets are not foldable, but rigid.
Who do not mind the price and a Nerf glasses likes may strike confidently.
ALTERNATIVE: Enough also a cheap "drug store" glasses (eg sunglasses.) To protect the eyes. The come in many variations and determined even under 15, -EUR.