I had PRK 6 weeks ago and still do not have clear vision. It hasn't seemed to change much since 3 weeks ago.

I had PRK 6 weeks ago and my vision is still not clear. I am seeing about 20/40 on an eye chart but the blurriness comes and goes throughout the day. I can see well in daylight almost as well as with glasses, but in low light i am still not seeing well. Does this seem normal? From what I read, most people are seeing 20/20 after the first month. My doctor said it could take another 6 weeks and said my eyes are dry. I am completely discouraged.