You should drink eight glasses of water a day, reading in dim light damages your eyes, and shaving your legs makes the hair grown back faster, right?

Wrong. These medical myths are among seven theories exposed in a paper recently published in the British Medical Journal.

According to Reuters, two U.S. researchers took seven common beliefs and searched the archives for evidence to support them.  One they tried to disprove was the need to drink eight glasses of water a day. Guess what? They found no scientific basis for the claim. They recorded the complete lack of evidence in a study published by the American Journal of Psychology, they said.

The other “myths” are:
* Reading in dim light ruins your eyesight - The researchers said the majority of eye experts believe it is unlikely to do any permanent damage, but it may make you squint, blink more and have trouble focusing.
* Shaving makes hair grow back faster or coarser - Studies say shaving has no effect on the thickness or rate of hair regrowth, but stubble lacks the finer taper of unshaven hair, giving the impression of coarseness, the researchers said.
* Eating turkey makes you drowsy - While turkey does contain an amino acid called tryptophan that is involved in sleep and mood control, the researchers discovered that it has no more of the acid than chicken or beef. Eating lots of food and drink at Christmas are probably the real cause of sleepiness, they said.
* We use only 10 percent of our brains - This myth has been around since 1907. The study found that imaging shows no area of the brain is silent or completely inactive, Reuters said.
* Hair and fingernails continue to grow after death - The researchers said the skin dries out and retracts after death, giving the appearance of longer hair or nails.  According to Reuters, this idea may originate from ghost stories.
* Mobile phones are dangerous in hospitals - Despite widespread concerns, researchers said studies have found minimal interference with medical equipment, Reuters reported.