Dr. Peter Ostrow is putting some of the most popular medical myths under the microscope.

Has anyone told you that reading in dim light can hurt your eyesight? Do you believe it? That's wrong. It may be difficult to read in dim light, but it won't harm your eyesight. It turns out that a lot of folklore about health is wrong.

Most of us don't speak with a doctor very often. Instead, we have lots of other sources of health-related information. Some of it is true, but some is just folklore.

Ostrow asked Dr. Stan Schwartz, the Chief of Rheumatology at UB Medical School, and by the way, he cracks his knuckles.

"Absolutely, I like to. When I can, it doesn't always work, but sure," said Schwartz.

His mother didn't warn him about it, and neither does medical science.

"When it comes to just casually or even repetitively cracking your knuckles, I am not aware of an consequence, of any medical consequence, like arthritis. It seems to be a fairly benign process," said Schwartz.

Have you heard that shaving makes your hair grow faster and thicker? That's not true. In the included video, there is a diagram that shows how hair grows from follicles beneath the skin surface. As the hair lengthens, it becomes thinner and more flexible. When you shave it off, new hair continues to grow at the same rate, about a half inch a month. When you feel the short stubble of new hair, it feels coarse to the tough, but it's the same thickness it always way, the long part you shaved off was thinner.

Have you heard that eating nuts can cure a toothache? It won't.

UB Dental School's Dr. Sebastian Ciancio said, "There is the possibility that some of the nuts have salicylate, which is what's in Asprin, and so that's how that myth may have started, but I know of no single study anywhere in the world that shows that chewing nuts with help relieve toothache."

There are things that will relieve toothache, like oil of clove or benzocaine.

"Put that on the spot where you have the toothache, and it relieves the pain almost immediately," said Ciancio.

But if you have a cavity, pain relief is not enough.

"These are all going to help you temporarily," said Ciancio. "But once the hole is in your tooth, the decay has to be removed. It has to be filled."

If you're tempted to try eating nuts for a toothache, be sure to brush your teeth and floss afterward, so then nuts don't get stuck in your teeth and make things worse.

As for thousands of other medical myths out there, we'll be looking at them as a regular feature on upcoming health reports, it should be fun.