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Vampire bats have a natural anticoagulant in their saliva that permits continuous bleeding after they painlessly open a wound with their incisors. This capillary blood does not cause any significant blood loss to their victims.
Pink eye is a term that refers to conjunctivitis, which is inflammation of the thin, clear membrane (conjunctiva) over the white part of the eye (sclera). It may be triggered by a virus, bacteria, or foreign body in the eye. Antibiotic eye drops alleviate bacterial conjunctivitis, and antihistamine allergy pills or eye drops help control allergic conjunctivitis symptoms.
A cataract is a clouding of the eyes' natural lens. As we age, some clouding of the lens may occur. The first sign of a cataract is usually blurry vision. Although glasses and other visual aids may at first help a person with cataracts, surgery may become inevitable. Cataract surgery is very successful in restoring vision, and it is the most frequently performed surgery in the United States.
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.
The tallest man ever known was Robert Wadlow, an American, who reached the height of 8 feet 11 inches. He died at age 26 years from an infection caused by the immense weight of his body (491 pounds) and the stress on his leg bones and muscles.