To answer this question, it is important to distinguish between an optometrist and an ophthalmologist as people often confuse the two. An ophthalmologist is a fully qualified medical doctor who...
People can be doctors in more than just medicine like a doctor in science, or maths, or reading, even a dr of teaching. Dr. Seuss never obtained a PHD. He used it in his pen name to honor his fathers...
"The Doctor" is a name the character uses throughout the series since its beginning in 1963. The character's true identity has never been revealed, though there have been hints as to his back story...
Ruy Lopez De Villalobos named Philippines after Prince/King Phillip II of Spain, which is the king of Spain in that period. He named it after him because of his joy.