Calluses

I'm not new to playing guitar, but I've recently picked it back up with a vengance. I've always played pretty light strings, but now that my calluses have reformed to the point of being hard as nails, I'm wondering if I should switch to some heavier strings. I seem to have lost considerable sensativity in my finger tips and my fretting feels sloppy now. I just can't feel the string anymore. Is this just something to get used to, or will heavier strings allow me to feel what I am doing?