Why would a mask be effective at protecting other people from me but not effective at protecting me from other people?

Does it have a one-way valve?

So far, here's what we got

1. The mask isn't sealed on the sides so droplets can get in.

Doesn't that mean they can also get out?

2. People not wearing masks can get droplets all over stuff and you touch it

Then wash your hands. What does that have to do with the mask?

3. People can cough in your face

How often does that happen!?

4. Doesn't matter either way. Virus particles pass through it.

Then why does anyone wear a mask ever?

5. It can infect you through your eyes

I need to look into this one because this doesn't make sense to me either. COVID gets into the nose or mouth and causes an upper respiratory infection by infecting those cells. How the heck can it do that going through the eyes?