Should we be De-Evolving?

I think that humans in the western society are definitaly devolving physically. Whenever a man with horrible eyesight is allowed to reproduce, the eyesight of the genetic pool takes a tiny step down. Whenever a person who is only alive because of modern medecine and antibiotics reproduces, the level of immunity of the genetic pool takes a step down. Over time, people are becoming less physically strong and fit. Back in the caveman days, if you had poor eyesight, chances are you would die because you can't hunt well if you can't see anything. Modern society and modern science has made it possible for physically unfit people to live and reproduce, causing the fitness of humans to decrease. Think about this: I believe that if god made humans directly,(basic 7 day creation story, which i dont believe, but bear with me) he would have made us gentically perfect (which is why it was ok that eveyone was doing it with their cousins for the first few generations...) then humans can only devovle because we started out perfect(god meant for us to live forever, i assume we started out with a perfect immune system and such). Now i understand that it is an organism's environment that dictates whether a mutation will be positive or negative, and in the modern world physical prowess is not required, so my first examples of eyesight and immunity aren't very good today, but think, without modern science and medicine nearly everybody alive today would be dead.