Hurrah, we come to the end of the module! We started by wondering why pirates wore eye patches. The most likely reason has to do with seeing in the darkness.
We saw in the module that when we move from light to darkness, our eyes have to adapt to the darkness. It takes time for us to start seeing things in the dark.
Pirates would travel often from above the deck to inside the ship. Those days, there wasn't much artificial light inside the ship. So, the pirates would remove the eye patch and they would have an eye that is already adjusted to darkness. Smart, no!?