As you can see by the replies, you're not alone in your quandry. Rest assured, I'm here to help.

Take a cool shower (hot showers only irritate them more) and dab your skin dry gently with a soft cotton towel. Dry your hair, because you don't need to catch a cold on top of having itchy nipples. Then retire to your bedroom where the heat should be set at a comfortable temperature and lay on the bed, face up. Because I believe the problem lays in the realm of "sensitivity to light", you're going to have to accustom your nipples to brighter lights than they currently get all tucked away inside a bra, under a shirt. This is best achieved in small, yet powerful doses not unlike the flash of a camera. Regular cameras will work ok, but the added benefit of using a digital camera is that you can put all the pictures in one place (best if you use an alternate server like Pixies, so you don't run the risk of losing all of your medical research and data) and examine the pictures for subtle differences throughout the process. It may take several angles to assure even coverage, and might have to be repeated a few times before you notice a difference. I suggest a round of pictures every day for one week.

By the time one week is past, you'll have one hell of a thread and whatever is really the cause will go away on it's own.

__________________
Though I am different from you,
We were born involved in one another.

For it was not into my ear you whispered, but into my heart. It was not my lips you kissed, but my soul.

Complete surrender should not just come at moments in which one faces overwhelming odds, but in the calm when it seems one is personally in complete control of one's life.