The more he was challenged by professional astronomers, the more Herschel became conscious of his 'art of seeing', and how it needed explaining afresh. 'The eye is one of the most extraordinary Organs,' he repeatedly told his correspondants. Classical physiology was wrong. Visual images did not simply fall upon the optic nerve, in the same sense that they fell upon a speculum mirror. The eye constantly interpreted what it saw... The astronomer had to learn to see...Holmes suggests that Herschel's training as a musician aided his ability to observe the night sky. Like sight reading a score, Herschel could grasp patterns in the sky without needing to observe each star individually. "Or more subtly, the brain that was trained to recognise the highly complex counterpoints and harmonies of Bach and Handel could instinctively [italics mine] recognise analogous star patternings." (p. 115)
It occurred to me that perhaps we refer to Chazal as the "einei ha'eidah," the eyes of the people, because their power of vision is characterized by these same two aspects of "seeing" that Holmes describes. Firstly, seeing is not instinctive, but is a learned behavior, a skill, and a highly trained observer who has worked on developing his vision can perceive far more than the average person. Dismissing the words of a talmid chacham by saying, "I don't see his point," just highlights the paucity of our own vision in comparison to what the talmid chachaim does see. Secondly, our talmidei chachamim and einei ha'eidah have an instinctive grasp of reality that we may not share. To attempt to reduce what can be grasped instinctively and instantly into a series of steps that someone else can follow and duplicate is not always possible.
P.S. The book is pretty interesting (so far), whether you are looking for a history of science during the Romantic age or just a good read.