South America
In Brazil, a 2005 study estimated 6% of Brazilians between the ages of 12 and 59 had −1.00 diopter of myopia or more, compared with 3% of the indigenous people in northwestern Brazil. Another found nearly 1 in 8 (13%) of the students in the city of Natal were myopic. History
The difference between the near-sighted and far-sighted people was noted already by Aristotle. Graeco-Roman physician Galen first used the term "myopia" (from Greek words "myein" meaning "to close or shut" and "ops" (gen. opos) meaning "eye") for near-sightedness. The first spectacles for correcting myopia were invented by a German cardinal in the year 1451. Johannes Kepler in his Clarification of Ophthalmic Dioptrics (1604) first demonstrated that near-sightedness was due to the incident light focusing in front of the retina. Kepler also showed that near-sightedness could be corrected by concave lenses. In 1632, Vopiscus Fortunatus Plempius examined a myopic eye and confirmed that myopia was due to a lengthening of its axial diameter. Society and culture
The terms "myopia" and "myopic" (or the common terms "short-sightedness" or "short-sighted", respectively) have been used metaphorically to refer to cognitive thinking and decision making that is narrow in scope or lacking in foresight or in concern for wider interests or for longer-term consequences. It is often used to describe a decision that may be beneficial in the present, but detrimental in the future, or a viewpoint that fails to consider anything outside a very narrow and limited range.
While use in patients with aortic stenosis (narrowing of the aorta where it meets the left ventricle) since it does not inhibit the ventricles function is generally safe, it can still cause collapse in cases of severe stenosis. In unstable angina (excluding variant angina), amlodipine can cause a reflex increase in cardiac contractility (how hard the ventricles squeeze) and heart rate, which together increase the demand for oxygen by the heart itself. Patients with severe hypotension can have their low blood pressure exacerbated, and patients in heart failure can get pulmonary edema. Those with impaired liver function are unable to metabolize amlodipine to its full extent, giving it a longer half-life than typical.Amlodipines safety in pregnancy has not been established, although reproductive toxicity at high doses is known. Whether amlodipine enters the milk of breastfeeding mothers is also unknown.Those who have heart failure, or recently had a heart attack, should take amlodipine with caution. Adverse effects
Some common dose-dependent adverse effects of amlodipine include vasodilatory effects, peripheral edema, dizziness, palpitations, and flushing. Peripheral edema (fluid accumulation in the tissues) occurs at rate of 10.8% at a 10-mg dose (versus 0.6% for placebos), and is three times more likely in women than in men. It causes more dilation in the arterioles and precapillary vessels than the postcapillary vessels and venules. The increased dilation allows for more blood, which is unable to push through to the relatively constricted postcapillary venules and vessels; the pressure causes much of the plasma to move into the interstitial space.