What Causes Headaches And Watery Eyes?

My father, 89 years old, is (according to his doctor and recent cat scan) has recently begun to experience headaches in the top, right front of his head. His eyes seem to water some but not his nose. He has no energy on days that he has these headaches and they seem to last all day. The only advice given so far is to have an eye exam asap. Any ideas?