Your target or corsshairs are going to be a little fuzzy because they are on two different planes. the corsshairs are superimposed over the target. It should be just a little but if it is causing you to have groups that are 3 or 4" then I think it is your eye problem.
Go to your local sporting goods store. and ask to see a few scopes. Look at some cheap ones then have then get a Leupold or Nikon Monarch or other good scope out and look through it.