Blindfold

On its own, no. Darkness dims your screen and does nothing else, and the enemies that inflict it are not the ones that kill you. Giving up a movement or damage accessory to avoid a lighting problem you could solve with a torch is a bad trade in almost every situation. It also does nothing against the harsher vision debuffs, so it will not save you in the places where losing sight actually hurts.

It is a crafting component. Recent versions pulled it out of the Ankh Charm chain and pointed it at the Reflective Shades instead, and shimmer swaps it back and forth with the Pocket Mirror, so a single drop covers either of those immunities depending on what you are walking into. If a slime hands you one, throw it in a chest and forget about it until a recipe asks.