Not sure exactly what you're asking. Do scopes actually make your eyesight worse? NO. If you get used to shooting with scopes for a while, will you have trouble visually picking up the irons if you switch back? In my experience, NO. I shot many thousands of rounds using a scope on my old air rifle in the back yard, and my vision is still better than 20/20.
You might have to re-familiarize yourself to the sight picture with the irons on a particular gun if you've used crosshairs exclusively for a looong time, but it shouldn't take you more than a few shots.
If you need/want a scope, but one and use it, nothing to worry about. I'm thinking about an extended eye relief scope for my Ruger Mk II. I wanna see how the groups hold up beyond 50 yards, just for kicks.
I know that scopes are optics that’s why I asked; I notice that after I look at something through a magnifying glass for a while or use with binoculars my eyes kinda hurt or at least I have to blink a few times to get use to regular view.
As a Commercial Photographer for over 25 years and a Scoped hundgun shooter in IHMSA I can say this about optics, BAD glass (optics) WILL hurt your eyes and give you a headache(won't damage them).
When using ANYTHING with glass in it and looking thru it, don't skimp on price!
Put it up to your eye and steady it on something, and look thru it for several minutes with out it shaking all over. If you start to get a headache or your eyes begin to hurt put it down and look at other brands(after you have rested your eyes for about 15 minutes)
There is a reason why some scopes cost way more than others.
I have found that the Bushnell Trophy and Elite series of pistol scopes to perform very well for there cost. They offer lots of eye relief even at the highest magnification, and will take all the recoil you can punish them with.