I was taught the same about the red dot (like iron sights) but, you can keep both eyes open with little worry of parallaxing. I used to use one on my paintball gun, as I wasn't of the "paint the forest" mindset. However, in one instance, I didn't allow for distance (adrenaline) and my center mass 3-round burst ended up a center crotch 3-round burst. Yes, he's fine. Yes, he has kids now
Thanks guys, all the positive responses work for me.