I Just Performed an Eye Exam on Peter Parker aka "Spider Man"
Famously in both the comic book and the movies, Peter Parker wears glasses, until his spider bite. Then he suddenly sees perfectly and no longer needs glasses! Impossible you say? Well I just saw it happen with my own eyes! Read further b/c it's not quite as miraculous as you think! A patient came in this morning saying that a few weeks ago he had been bitten on the left upper eyelid by a spider. The bite caused his eyelid to swell up nearly shut and be "hard", full of infected material (I promise not to get too gross here), that's called "preseptal cellulitis". He was put on antibiotics by his primary care provider. The swelling subsided as the infection was treated, and when his eye started being open enough to see again he noticed that he now sees better out of the left eye WITHOUT his glasses! He came in telling me that he thought the poison from the spider bite made that eye not need glasses anymore! And when we evaluated him...he was right! His formerly nearsighted left eye was...NO LONGER NEARSIGHTED! It was "mixed astigmatism", and his uncorrected acuity in that eye was 20/25! So here's the skinny: the swollen, hard left upper lid temporarily deformed/distorted/flattened his left cornea, temporarily eliminating his myopia (but inducing astigmatism) making his myopic glasses blurry and his uncorrected vision in that eye BETTER. The topographical map shows central and superior flattening ("ortho-k" effect) from the constant pressure of the swollen/hard/closed left eyelid. Pretty interesting! Unfortunately I had to inform him that it was not the "poison" (not directly, anyway) that caused his vision to improve, and that sadly this was a temporary effect and will wear off when his corneal distortion resolves after his eyelid swelling goes down. Ah well. It was too good to be true anyway!