My beardies love them too, but you have to squish them first! (The blueberries, not the beardies!!!)
According to h**p://www.beautifuldragons.503xtreme.com/Nutrition.html Blueberries are an ok occasional feeder, but shouldn't be a main staple of your beardies Diet.
Blueberries (fresh)
Ca
1:1.6
Protein .7%
Fat .4%
Fiber 2.7%
Sugars 7.3%
Water 85%
Moderate oxalates
This is a pretty awesome list, and my go to for determining if it's ok to feed my beardies something. I've been using it for some time with success.
Macpunk