AR-15s

I too wear bifocals and as a result had to switch to red dots on my ARs. Once you get thru the transition phase you will like them. Gzig gives you a darn good suggestion on an entry level type optic. Go to a good big box type sporting good store and just look thru a bunch of them till you find one you like. There is a lot of options, one of them will likely suit your needs.