Summary
No masks blocks the corona virus. The mask is designed to decrease the probability you will spread the virus. It protects you if you are an individual that has a habit of putting your unclean hands in your mouth or nose. Because there is no 100% solution available for 100% of the time for 100% of the people, the
Poisson distribution comes into play. The use of masks may change when you get the virus. It is technically possible, that you could extend when you get the virus until after the scientific community finds a solution. The vaccines are not the solution, but that is another topic.
P.S. The people that claimed to have debunked the below meme are wrong. The mask does not stop ALL respiratory droplets. Once again Poisson distribution comes into play.