Questions about sights on my M1a loaded

[texas30cal]

I didn't really know where to post this, move if necessary. The rifle shoots great but the hole in the rear sight is so large that when focusing on the front sight it is very hard to tell if I have the front sight in the center, also it is very blurry to me, I understand that I can't focus on both at once, but I can't even make out the edge of the hole. My eyes aren't perfect but could they be the problem? I don't have any problem with any of my pistol sights but even my 10-22 and henry 22 look the same way to me. Is this what the sight with the hood and smaller hole is for? I also saw a gentleman that actually makes lenses that go in the hood, does anyone know anything about these?

[98Z5V]

Is this what the sight with the hood and smaller hole is for?

Yep.  Hooded National Match rear sight.  <thumbsup>

[N Jensen]

A little more info, the hooded rear sight comes in two sizes .520 and .595 you also will have a the ability for 1/2 min adj by turning the hood 1/2 turn to the next detente. You mention that the front sight is blurry? With the hood installed you can insert a diopter into the hood and that will help with the front sight focus. Check out this link http://www.bjonessights.com/SR.html the cost isn't bad to get a front sight in focus.  Also installing the rear sight can be worked so the end result is good clicks up and down and without any play. Not many sights go together and end up without any play in them. If you have any play sided to side that can be felt the group on target will be big as well. Steps to fix it are out there and isn't that hard to do. I assume the windage knob has a spring and ball underneath it. If it does you are half way to a 1/2 min rear sight on your rifle, just buy the hood and slide.  Good luck. 

[texas30cal]

Thank's for the replies, I meant that the front is clear but the rear is very blurry, but I understand I can't focus on both. Is that what the diopter is for?

[N Jensen]

Yes, the diopter helps one to focus on the front sight.

[98Z5V]

Thank's for the replies, I meant that the front is clear but the rear is very blurry, but I understand I can't focus on both. Is that what the diopter is for?

Normal.  You don't focus on the rear sight - you focus on the front sight.  You should see the front sight clearly, and the rear should be blurry, if you're doing it right.  <thumbsup>

Pic of proper "Sight Alignment" from the US Army Marksmanship Manual - click the pic, and it'll appear full-size: