what causes astigmatism?

Astigmatism - Astigmatism is the most common vision problem resulting in distorted images, as light rays are prevented from meeting at a common focus. Astigmatism may accompany Hypermetropia or Myopia What Causes Astigmatism? Normally the ..

Astigmatism - At times the eye is not able to focus the light coming from the horizontal and vertical planes. As a result, the horizontal and vertical views of an object will not be the same. Such a defect of the eye is called astigmatism. Astigmatism occurs when the e..

Astigmatism is the most common vision problem resulting in distorted images, as light rays are prevented from meeting at a common focu..

Kidney failure is caused due to many reasons: (a) Tubular injury (b) Infection (c) Bacterial toxins (d) Inflammation of glomeruli (e) Arterial or venous obstruction (f) Fluid and electrolyte depletion (g) Intrarenal precipitation of calcium and urates. (h) Drug reaction (i) Haemorrh..

1. The parents of these students do not place much importance on education. At the least provocation, they take the children out of school. Girl students are especially vulnerable. For them the household chores - carrying water, looking after siblings and marriage are considered more important. 2...

The main cause of soil erosion is the removal of vegetation. Vegetation removal takes place due to removal of forest covers. Unscientific farming has also led to barren lands. The removal of vegetation exposes the topsoil to water and wind. Water and wind cause the topsoil to be..

Causes of Pollution - The ultimate cause of pollution is human activity itself. Pollution is a human contribution to nature. Science has evolved technologies and technologies have helped the human welfare. In the process, the pollution has been a part of technology and therefore..

It is a disease caused by a retrovirus called HIV that can be passed from one person to another chiefly during sexual contact or through sharing of intravenous drug needles and syringes. A pregnant mother who is infected with HIV can pass the infection to the foetus. The infection can als..

The ultimate cause of pollution is human activity itself. Pollution is a human contribution to nature. Science has evolved technologies and technologies have helped the human welfare. In the process, the pollution has been a part of technology and therefore a part of human miseries. Human..

Hypermetropia is caused due to the following reasons: Shortening of the eyeball, that is, the eyeball becomes smaller. Increase in focal length of the eye lens. Focussing of light rays in normal eye and long sighted eye Let us now see how this defect is rectified. A long sighted eye forms..