Here is an info-graphic on how to choose binoculars from Binoculars Today. I hope this is useful to you. I don’t normally post infographics, but this one seems to have some useful information for you.
It talks about what the numbers like 109×50 mean. It also gives some information on lens coatings and prism types.
This info gives some good basic information, but if you want to know more you can visit their website, or look at the book I linked to at the top left of this article.
When I was an older boy scout we organized a large capture the flag event and spent months preparing to win the contest. It was during that time that I learned that a good pair of binoculars gathered light and made it easier to see at night. It wasn’t night vision by any means. When the moon is out providing some ambient light binoculars can help.
I hope this picture will help you better know how to choose binoculars. Good binoculars can make the difference in many outdoor and prepper activities. You should have a decent set in every prepper kit you own.