You could try to convince your DM to change your race to Dragonborn of Bahamut, which is in Races of the Dragon, if memory serves correct. If you choose the right ability (yes, you get to choose one out of three!), it gives you darkvision and low-lightvision that improves with your HD, and at 15th level you even get Blindsense.
The race change is neatly described in the book itself, so that shouldn't be too hard to accomplish. The -2 Dex, +2 Con and the loss of some of your initial racial abilities would be something to consider though. If you have a Dex based character, this may not be a good thing for you.