Shooting glasses question...

[harvey_s]

I shoot 10m air pistol competitions and have thought about adding a proper pair of shooting glasses to my kit...
I wear glasses with about a -4.5 perscription, I understand that the glasses will need a correction of about +0.5 to focus on the foresight....but here's the question - I notice a lot of the guys with specialist glasses use an iris.
but just while mucking about I find that if I look through a very small hole the vision in the eye seems to improve dramatically....is this normal? and will different iris sizes mean I need different perscriptions for each iris size?

[Hurricane]

but just while mucking about I find that if I look through a very small hole the vision in the eye seems to improve dramatically....is this normal?

Don't know anything about rest of your question, but yes this is normal.

[big_phil555]

I wear glasses too mate

i use the clip on iris and this really does sharpen up the foresight picture no end

mine is made by centra and I got it from edinkillie

[RobF]

iris will deepen the depth of field, deeper the smaller the aperture... i can tell you how to set one up for 10m rifle, but i'd suggest awaiting a pistol shooter for more correct advice.

[big_phil555]

good point RobF

you need to make sure you get the right one for yor shooring discipline

[RobinC]

Hi Harvey
It will make a significant difference and is a good move, as for the prescription, it is basically about getting a lens of focal length to the foresight, but there are some variations so it is best to see an opticion and get it prescribed. We are lucky in Norwich with having an optician who is interested, He did mine with a test frame with the pistol on aim until I was happy with the sight picture and then set up 10 mts in the shop to check that I could still find the blurred target! I initialy used an iris which acts a little like a fine tune of the focus, but found that it also sharpened the focus on the target and tempted my focus away from the foresight so I have stopped using it.
I also have a list of shooting goodies that a contact is selling including some Knobloch frames which I'll bring on Tuesday, so you could be a lucky boy!
See you Tuesday, we can talk then.
Best regards
Robin