I just switched from 112 mg of synthroid. I started at 1 grain of Nature Throid. I didn't feel too much different except started to have some minor headaches. After 2 weeks, my vision really started to be affected. I had a hart time focusing my eyes. Reading and looking at the computer became almost painful. My headaches became more severe. I thought maybe I needed more meds, and so increased to1 1/2 grain. However, it doesn't seem to have helped (or increased the headaches). I just had a period that lasted 10 days - which I know has to be related to the thyroid issue. Anyway, I'm wondering if I'm on too much or maybe not enough? Or if I am having some kind of reaction - I read in one post that some people who have hashimotos (mine) occasionally develop TED when put on dessicated thyroid "Some people develop TED when they take animal-based extracts such as Armour, because the immune system react to foreign proteins found in glandular extracts. Synthetic meds. doesn't cause this problem. ". I don't know the validity of this, but it's seems plausible. I probably need to contact my doctor, but she is already determined that 1 1/2 grains to 2 is the max anyone should have (I've read that 3 is often optimal for many). I'm not having palpitations are digestive problems, but I do have frequent but minor night sweats. Any ideas?