Parasites are living things that use other living things – like your body – for food and a place to live. You can get them from contaminated food or water, a bug bite, or sexual contact. Some parasitic diseases are easily treated and some are not.
Parasites range in size from tiny, one-celled organisms called protozoa to worms that can be seen with the naked eye. Some parasitic diseases occur in the United States. Contaminated water supplies can lead to Giardia infections. Cats can transmit toxoplasmosis, which is dangerous for pregnant women. Others, like malaria, are common in other parts of the world.
If you are traveling, it’s important to drink only water you know is safe. Prevention is especially important. There are no vaccines for parasitic diseases. Some medicines are available to treat parasitic infections.
The retina is a layer of tissue in the back of your eye that senses light and sends images to your brain. In the center of this nerve tissue is the macula. It provides the sharp, central vision needed for reading, driving and seeing fine detail.
Retinal disorders affect this vital tissue. They can affect your vision, and some can be serious enough to cause blindness. Examples are
- Macular degeneration – a disease that destroys your sharp, central vision
- Diabetic eye disease
- Retinal detachment – a medical emergency, when the retina is pulled away from the back of the eye
- Retinoblastoma – cancer of the retina. It is most common in young children.
- Macular pucker – scar tissue on the macula
- Macular hole – a small break in the macula that usually happens to people over 60
- Floaters – cobwebs or specks in your field of vision
NIH: National Eye Institute