I have a Colt HBAR postban, flattop with carry handle with the peephole sight.  I just can't see a damn thing thru the sights, they are virtually useless.  Can anyone recommend a better set of iron sights, or an optical sight that is good out to about 100 yards, and isn't too expensive, and would move the rear sight up higher than it is now?  Thanks.

See the Eotech threads.  After using the first one for just one outing at the range, I ordered two more.  Mount it directly to your flattop's rail.  

I bought the 512, which uses AA's, not N batteries.  N's are tiny things that give 70 hours usage, which is good.  AA Alkalines give 300 hours.  AA Lithium (Photo) give 500 hours.

This will set you back about $340 or so.  You could also consider the Bushnell Holosight, which is basically the same, but uses the N batteries, and lacks the metal "roll cage", for about $250.

You shoot these things with both eyes open, looking at the target.  The reticle appears to be way out front.  You don't have to align anything, whereever the reticle is, that's where it hits (once sighted in).  This is the easiest, fastest sight I have ever used.  There is no magnification, but it fast and accurate.

The AR-15's Aperture sights "virtually useless"?

Somehow I think its your eyes that are 'virtually useless" if you are having issues with the AR's irons.

Optics though are a good thing and you have many choices.

Tell us what you want to do with the rifle and what your budget is and we can suggest some options for optics.

my eyes only work with peeps if i pull back off the sight.  i need a good 2-3 inches from the rear sight to my eye to be able to see the front sight.  if i am too close it just fuzzes out.  at about 3" it is clear.  

You are focusing on the front sight when aiming, not the rear one, right???

 

Is this ONLY with this particular set of irons on this particular rifle?

What size rear peephole do you have?  You might try a larger one if you are having problems.

When using the AR's peep sight, touch the tip of your nose to the charging handle.  Do not worry about seeing the the rear aperture.  Let it fuzz.  If you can see the front post, you will center you eye on the hole.  Focus on the front sight post, not the target.  NO ONES eye can focus on the rear sight, front sight, and target simultaneously.  

For 0-200 yds, use the big hole on the rear sight.  It is fast, and plenty accurate enough.  Leave it on the large hole for most quick shooting.  This is a battle sight, not a target sight.

The small hole is for greater distances.

If you normally wear glasses, try without glasses with the small aperture.  This forms a type of pinhole camera effect, and you would be surprised at how well in focus everything is.

I still recommend the Eotech and/or Bushnell Holosight to you.