Problems with diopter sight

[xopher]

Just dug out my Izhmash 22lr rifle with diopter sights and i noticed something odd with my rear sight.

For those who are familiar with these, i basically match up and center a series of circles.

For some odd reason, my rear size doesn't seem to be perfectly circular...its more of an oval or sometime the bottom is flat...

I have inspected the rear metal insert closely and it is perfect...

What might be causing this odd "distortion"?

Could it be my sights arn't in line in terms of height? If so, are there anyways to fix it?

Thanks in advance!

 

[brnolvr]

Check for small dust particles in the eyepiece, blow out with compressed air, doesn't take much to block view trough those small apetures.

 

[dryfire]

Rotate the rifle 90 degrees around its linear axis and look through the sight. If the distortion moves with the rotation it's the sight , if the distortion always appears at the 6o/c or the same shape it's your eye.

 

[horseshoe]

Rotate the rifle 90 degrees around its linear axis and look through the sight. If the distortion moves with the rotation it's the sight , if the distortion always appears at the 6o/c or the same shape it's your eye.

Yup. Look through it "Gangsta style". At least you will know if it's your eye or if it's worth looking into the sight further.

And yes, it only takes a VERY tiny particle of dust in the aperture to have that happen. Is it variable aperture, like an iris, or interchangable apertures?

 

[ilike22s]

How old are you? All my aperture sights have magically gone from perfectly round to oval shaped. The axis of the oval is also diagonal regardless of orientation. Weird.

I wear glasses now but that doesn't change the odd shape.

 

[dryfire]

You may want to have the eyes checked for onset of cataracts or an astygmatism related to aging eyes. There is no specific age that sight degradation occurs even though many impairments are age related.
Fortunately my eyesight is maintaining well even though I'm near 60.

 

[ilike22s]

You may want to have the eyes checked for onset of cataracts or an astygmatism related to aging eyes. There is no specific age that sight degradation occurs even though many impairments are age related.
Fortunately my eyesight is maintaining well even though I'm near 60.

Yup! I was aircrew for 38 years and went through yearly eye exams. My last check detected a very slight astigmatism in my dominant eye. Most likely brought on by age, as it went undetected until now. Still have 20/20 in my left eye, and surprisingly 20/15 in the right/dominant eye. It was always my super eye. Unfortunately, it is my shooting eye as well.

The glasses to correct said astigmatism are very pricey but, I love to shoot.