For example, some medications, like steroids, can produce blue sclera. Not having enough iron in your blood (anemia) and aging have also been shown to give a blue tint to the whites of the eye.
While most cases of sclera discoloration are benign, they can sometimes be a sign of something more serious like Osteogenesis Imperfecta, Ehlers-Danlos Syndrome, Russell Silver Syndrome, Pyknodysostosis, Hallermann- Schermann-Streiff syndrome and Marfan Syndrome.
It is important to note that all of these diseases are extremely rare and have other obvious symptoms as well. Anyone with a blue sclera may want to see an ophthalmologist to rule out these possibilities.