On June 26, OnStage Playhouse opens "Isaac's Eye," a play about renowned 17th-century scientist Isaac Newton and an experiment involving a very large needle. (Check out Newton's drawing of the experiment.) At Onstage Playhouse last Wednesday night, it was hard not to notice the 12-inch upholstery needle prominently sitting on the table at rehearsal. The clue to its purpose lies in the title of the play, "Isaac’s Eye." Director James P.