Refraction is also reflection? Or a bug?

Im trying to make a heatwave shader using Shaderforge. After setting it all up and getting it to look nice, I saw a problem, it looked like it was affecting the edges of objects infront, whereas I presumed it was only supposed to effect anything behind it. I did some testing, I put a vector 2 straight into the refraction slot, disconnecting my other nodes. Now that i had a constant value for the whole refraction input, I saw that it seemed to be reflecting / refracting objects infront of it, aswell as objects behind it. The image shows what happens when I give the refraction input a value of 0.5, 0. Pretty much a pure reflection.

Is this normal behaviour? Am I doing something wrong?