Why is this black bandage on the pirate's eye?

You have often seen in Hollywood and Bollywood movies that a ship is going to sea and it has a blindfold on the head of the pirate, so did you ever know that a pirate has black on his eye? Why does the bandage tie?

Let us tell you about it.

The blindfold of a pirate is the most popular movie in history. However, there is a well-known theory that blindfolds are common among seafarers, as their eyes are constantly exposed to darkness. It worked when someone had to go under the deck and look in the dark.

Because of this they could see immediately in the dark. It usually takes some time for the eye to adapt to seeing in the dark. This also seems acceptable because it usually takes a full 25 minutes for the eye to see in the dark. But this thing is not very useful in combat.