TargetTalk

I have a HW air rifle with the HW match aperture rear sight, and the tunnel front sight. The airgun is used for 10m shooting, and outdoor plinking at various ranges, so I am trying to stay with the post insert instead using of the aperture insert. The aperture that came with the rear sight is 1.6mm, and at times is too big or small. I would like to get an adjustable iris eyepiece. My aging eyes are having trouble getting a decent focus on the 10m bull, and at targets further outside. I know the target is supposed be slightly out of focus, but I cannot get clear definition of where the front sight ends and the bull begins, inducing elevation errors. The front sight is in clear focus. I have been told that a eyepiece with a 1.5mag, -4.5 to +4.5 and filters will help clear things up. I was ready to buy one, but now I see there are front sight optics that people are using, such as Eagle Eye and others, and they claim they can even read the target numbers at distance, using just an adjustable aperture only on the rear with the optical front. I am totally lost on this, and I know of no one who has these sights that I could test out. Which setup is normally better? How are the front sights measured? I see 18mm and 22mm sizes. Could anyone give me some insight on the pro's and cons of these sights and which setup would likely be better for my use?