AR-15s

Welp, everything is here. My new FFL guy is a trip. He's a nurse and said he's a libertarian anarchist. Said he wants left alone and wants to leave others alone. lol I can respect it.

Just installed the Magpul sights. Don't like needing a tool to adjust the front sight.
Was looking at red dot sights and came across 'co-witness'. Any help on that ?
I need something an old man that wears progressive lenses can use to see and quickly acquire a target. The rear sight hole is blurry with my glasses. I came across this, seems it works at night and is highly rated for the money.
https://www.amazon.com/dp/B01C95I8N4/?tag=fabo03-20