How exactly did George's non-existence cause Mary's eyesight to worsen?Many viewers have noticed, in George's reality, Mary does not wear glasses. In the alternate reality, however, she is shown wearing glasses: apparently, merely as a dramatic device, to symbolize her profession of librarian.The most common in-universe explanation is that Mary spends so much time reading (possibly in dim light), she ended up straining her eyes. Alternatively, in George's reality, Mary did not read a lot, so she didn't need glasses. Both explanations are based on the idea that reading too much causes one to need glasses: an idea prevalent in the 1940s but since disproven.Others speculate, Mary needs glasses in both realities, but doesn't wear them in George's reality, because it was a popular belief in the 1940s that "boys don't make passes at girls who wear glasses." This does not consist with her more accurate aim, earlier in the film, when throwing stones to make a wish; but the combination of these images, suggests she is farsighted (i.e., better able to see at a distance than nearby). It is also speculated, Mary in the alternate reality suffered an illness that might not have happened, had George been there (presumably to look after her, or to recommend her to a doctor in time).The most likely explanation is, the screenwriters were exploiting a common stereotype of older, unmarried woman dressed in glasses and dowdy clothes, with their hair in buns, who serve as librarians, teachers, or nurses. They also gave her a rather ungainly way of walking in this
One running thread through the movie involves drug store owner Mr. Gower. Drunk, heartbroken and grieving over the death of his son to the flu, Gower almost ends up poisoning a child because he was so distracted he didn’t pay attention to the medication he prepares for a child with diphtheria. But Young George, who delivered medications for Mr. Gower, takes note of the poison in the jar and brings it up with Mr. Gower. Gower simply sends him away so he can be alone to grieve. When Gower finds out George didn’t do his job, he slaps him until he bleeds. George explains the danger they avoided, Gower finally realizes what happened, and together the two keep it a secret.
If it's the content of the scene rather than your failing to understand the scene that upsets you, then maybe you should stop watching films altogether?