7 Medical Myths Even Doctors Believe.LiveScience.com.Dec 20, 2007. Popular culture is loaded with myths and half-truths. Most are harmless. But when doctors start believing medical myths, perhaps it’s time to worry. In the British Medical Journal this week, researchers looked into several common misconceptions, from the belief that a person should drink eight glasses of water per day to the notion that reading in low light ruins your eyesight. [ See ] Image from article in  Spanish.