|
|
People who have myopia, or nearsightedness, are not able to see objects at a distance but only up close. It occurs when the cornea is either curved too steeply, the eye is too long, or both. This condition is progressive and worsens with time. More than 100 million people in the United States are nearsighted, but only 20% of those are born with the condition. Diet, eye exercise, drug therapy, and corrective lenses can all help manage nearsightedness.
Giardia is one of the most common intestinal parasites worldwide, and infects up to 20% of the world population, mostly in poorer countries with inadequate sanitation. Infections are most common in children, though chronic Giardia is more common in adults.
Not getting enough sleep can greatly weaken the immune system. Lack of sleep makes you more likely to catch a cold, or more difficult to fight off an infection.
The Romans did not use numerals to indicate fractions but instead used words to indicate parts of a whole.
Chronic marijuana use can damage the white blood cells and reduce the immune system's ability to respond to disease by as much as 40%. Without a strong immune system, the body is vulnerable to all kinds of degenerative and infectious diseases.
![GI endoscopy. (a) Similar to other forms of GI endoscopy, laparoscopy involves the insertion of a sp](https://biology-forums.com/gallery/47/medium_14755_26_10_12_5_23_54_96921540.jpeg)
![In some species, dominant females have more surviving offspring that mature earlier indicating an ad](https://biology-forums.com/gallery/47/medium_269691_26_01_15_5_57_41_204522328.jpeg)