I second HouseWolf. I have only dealt with jrh enterprises. I wouldn't recommend anything less than 1600FOM and prefer 1900FOM. Both of these units he carries are 25.1SNL I believe. I also recommend getting a quality tube. I like a white tube but green works just fine for me. With that said I have 20/20 vision with no other eye problems.
This is a beginners guide to specs and if you cruise around within this site you will find some other interesting NV topics
https://www.nite-walker.com/post/201...or-dummies-101
Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you. And behold, I am with you always, to the end of the age.”