I Was a Teenage Optical Engineer

Lawrence Talbot, the Wolf Man of Universal horror films of the 1940s was played by Lon Chaney, Jr. Surprisingly, the character was an optical engineer in the original movie. He installed a telescope in the Talbot family home. In the original script, in fact, he is not even a relative of the family, but was brought in explicitly to install the telescope. Few things in a movie script are left to chance, but are either inspired by events, or else have some symbolic significance. Why did screenwriter Curt Siodmak settle upon someone in Optics for this role, when he might have used any profession as a means of inserting his character into the story?