Theia was a Titan, but is a goddess now. She is the goddess of sight. Her name means divine and her surname means wide-shining. She is also the goddess of enlightment, because in an eye, people need the light to see. It would be quite obvious that she is the goddess of sight. She is also the goddess of fire, but that is a minor power trait of hers that she can wield.
Theia's symbol would be known as a pair of glasses, due to sight.
She is good at fighting in wars, and she was believed to have invented glasses for the people who couldn't see as good as she sees. She claims she can see anything that is more than a mile away, better than any other Olympian in Olympus.
Theia's full name is Theia Euryphaessa. Euryphaessa is also the mother of Helios, the sun god, but is quite unknown.
Theia's official Greek name is Θεια.