The distance spec. when they refer to parallax is basically where a slight change in the positioning of your eye to the scope is not going to change where the crosshairs line up on the target,most scopes are set at 100yds. If you plan on doing close range target/squirrel hunting then something set around 50yds would be ideal. If you were to invest on one of the high quality .22 scopes I think you'd be safe, they are set at 50 usually. The only time I've actually had a problem with a scope due to this was a cheap scope that I briefly had that had memissing groundhogs at 50 feet, yet at 100 yards could knock there eye out. The thing is that when you shoot off a bench and then throw the gun to your shoulder while offhand shooting you do hold the gun differently enough to look through the scope at a slightly different angle. I think better scopes have less of an issue as far as howmuch this effects a shooter's aim, but all scopes by design have it. If you set a scoped gun on a set of sandbags lined up on a target and move your head around while looking at the crosshairs and see them move on the face of the target you'll see what they are talking about. In theory at the range of parallax free setting you will see no change.