|
|
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.
Everyone has one nostril that is larger than the other.
There used to be a metric calendar, as well as metric clocks. The metric calendar, or "French Republican Calendar" divided the year into 12 months, but each month was divided into three 10-day weeks. Each day had 10 decimal hours. Each hour had 100 decimal minutes. Due to lack of popularity, the metric clocks and calendars were ended in 1795, three years after they had been first marketed.
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.
The Food and Drug Administration has approved Risperdal, an adult antipsychotic drug, for the symptomatic treatment of irritability in children and adolescents with autism. The approval is the first for the use of a drug to treat behaviors associated with autism in children. These behaviors are included under the general heading of irritability and include aggression, deliberate self-injury, and temper tantrums.
![Cataract extraction. The procedure involves a surgical removal of a cataract lens and its replacemen](https://biology-forums.com/gallery/47/medium_14755_14_10_12_6_37_46_9400219.jpeg)
![Angioplasty. One form is called balloon angioplasty, shown here. A balloon catheter is threaded into](https://biology-forums.com/gallery/47/medium_14755_11_11_12_7_14_26_100251196.jpeg)