|
|
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
The most common childhood diseases include croup, chickenpox, ear infections, flu, pneumonia, ringworm, respiratory syncytial virus, scabies, head lice, and asthma.
Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.
If you use artificial sweeteners, such as cyclamates, your eyes may be more sensitive to light. Other factors that will make your eyes more sensitive to light include use of antibiotics, oral contraceptives, hypertension medications, diuretics, and antidiabetic medications.
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.