|
|
Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
No drugs are available to relieve parathyroid disease. Parathyroid disease is caused by a parathyroid tumor, and it needs to be removed by surgery.
Complications of influenza include: bacterial pneumonia, ear and sinus infections, dehydration, and worsening of chronic conditions such as asthma, congestive heart failure, or diabetes.
Egg cells are about the size of a grain of sand. They are formed inside of a female's ovaries before she is even born.