the amount of uv protection provided by a pair of sunglasses is independent of the amount of tint. some dark glasses can provide little uv protection and some lightly tinted glasses may provide 100% protection. the key is to read the label on the sunglasses. look for an indication that the sunglasses provide 100% uv protection; these glasses may be labeled uv400 instead. another key to the amount of uv protection will be the lens material. polycarbonate lenses generally provide 100% uv protection whereas cr-39 plastic provides 88% protection and cheap triacetate lenses only confer 40% protection.
do darker sunglasses provide more protection for the eyes than sunglasses that are less tinted?