Mcro red dot or iron sights

[Harry2110]

Im looking for a alternative sight for my glock 22 as i cant really use the stock night sights because of vision issues. Would something like a micro red dot like the trijicon rmr or would a alternative iron sight like a xs big dot, ghost ring, advantage tactical work better?
Are there any major advantages or drawbacks i should know about first?

Also does any store in Indianapolis carry such an item?

 

[Manatee]

What is the primary use of the firearm? I like the XS sight for defensive uses. It's a little large for plinking/competition (at least for me).