I had poreless skin before trying retin a 3/4 times. I used .5 but followed directions as I was told. I did not get red and barely flaked. My pores opened ALL over my face and have stayed that way for 2.5 months. This are my pores shrank down much smaller then when retin a first opened them. Why? What are those lines? As my skin heals, the pores turn into lines. Why can no doctor answer this question?