If you are familiar with Elex 1, the sunglasses have the same use in the new Elex 2. They are used for exploring the world and can mark animals, enemies, and plants.
More importantly they can mark legendary items. These are 29 items that are uniquely named and stand heads above other items in the game. Things like the steel net which reduces damage by 100%, the death stick which deals more than 400 damage, and the wrathful which deals over 500 damage.
Each unique item comes with flavor text, for example the wrathful’s is “let wrath rain down on your enemies.” Not very unique ironically, but it is what it is.
How to Get Sunglasses In Elex 2
The Sunglasses in Elex 2 are located near Marwin’s hideout where you can find two boulders and then bam you’ll see a loot box with them in it. If you can’t find them like that then walk on the unnamed road and look for a broken barrel sitting between 2 rocks near a body of water.