In chapter 674 page 9, Madara says that Sasuke is the only one who awakened a Sharingan with straight commas, just like his. After that, he says that there might be a connection between them, something beyond blood.
Does this mean that an Uchiha can be distinguished by their Sharingan? Does this also mean that the power of their eye is decided by the type of commas (tomoe) they have?