i know what this is! i have this blue tint also and it is a collagen disease! i have osteogenesis imperfecta a condition where i have a defect in making a type of collagen. this makes me a higher risk of fracturing my bones. it is genetic and a blue tint is a symptom. its not anything to worry about just as long as your careful not to fracture your bones!!
while i cannot answer your question, i just wanted to add that we sound very similar. Im 29 years old and all four of my daughters and i have the bluish tent to the whites of our eyes aswell. I wish i could find out what it means too....i hope its not PXE.