Lyme disease is an infection that is caused by a spirochete (a type of microorganism) called Borrelia burgdorferi, and more rarely by Borrelia mayonii. It is transmitted to humans by the bite of a deer tick.

The disease has a strong geographical...

The tears that coat the surface of your eyes have both a liquid and a mucous layer to them. It is normal to have a small amount of mucus in your tear film. But that mucus can significantly increase when the eye gets irritated.

Some of the most...