can any body tell me about colour blindness?

Question

anything about it like symtoms,effects,either it is cure able or not? etc

Answer 1

Colour blindness is usually genetic abnormality on the X-chromosome. To this, it is about 8-16 times more likely to affect men. In rare cases it can occur from disease or injury.

Typical symptons are an inability to distinguish certain colours. The most likely colours to be confused (99%) are red-green or red-green-brown, although others can occur, such as blue-yellow. Complete lack of colour is extremely rare.

The confusion occurs because the colour sensing cells (cones) in the eye come in three types - red green and blue-sensing. In a colour blind person, the sensitivity of one or more types of these cells is reduced, skewing the perceived colours toward the more sensitive cells.

Most colour blind people can distinguish some degree of reds/greens or whatever. There are certain shades of the colours that cause confusion, but pure primary colours are sometimes ok.

For sake, don't ask a colour blind person what colour they see! They don't know - they know from experience that they should be seeing red or green or whatever, but cannot determine which it is. It's like trying to describe a new colour to someone who's never seen it before.

A quick test is available at:
http://www.toledo-bend.com/colorblind/Ishihara.html

Answer 2

Color blindness, or color vision deficiency, in humans is the inability to perceive differences between some or all colors that other people can distinguish. It is most often of genetic nature, but may also occur because of eye, nerve, or brain damage, or due to exposure to certain chemicals. The English chemist John Dalton in 1798 published the first scientific paper on the subject, "Extraordinary facts relating to the vision of colours", [1] after the realization of his own color blindness; because of Dalton's work, the condition is sometimes called Daltonism, although this term is now used for a type of color blindness called deuteranopia.

Color blindness is usually classed as a disability; however, in select situations color blind people may have advantages over people with normal color vision. There is anecdotal evidence that color blind individuals are better at penetrating color camouflage and at least one scientific study (Morgan, Adams and Mollon, 1992) confirms this under controlled conditions. Monochromats may have a minor advantage in dark vision, but only in the first five minutes of dark adaptation.

Alot of information here with 3 good pictures to test colour blindness:
http://en.wikipedia.org/wiki/Color_blindness

Answer 3

Color blindness, or color vision deficiency, in humans is the inability to perceive differences between some or all colors that other people can distinguish. It is most often of genetic nature, but may also occur because of eye, nerve, or brain damage, or due to exposure to certain chemicals. The English chemist John Dalton in 1798 published the first scientific paper on the subject, "Extraordinary facts relating to the vision of colours", [1] after the realization of his own color blindness; because of Dalton's work, the condition is sometimes called Daltonism, although this term is now used for a type of color blindness called deuteranopia.

Color blindness is usually classed as a disability; however, in select situations color blind people may have advantages over people with normal color vision. There is anecdotal evidence that color blind individuals are better at penetrating color camouflage and at least one scientific study (Morgan, Adams and Mollon, 1992) confirms this under controlled conditions. Monochromats may have a minor advantage in dark vision, but only in the first five minutes of dark adaptation.

Causes of color blindness
There are many types of color blindness. The most common variety are hereditary (genetic) photoreceptor disorders, but it is also possible to acquire color blindness through damage to the retina, optic nerve, or higher brain areas. Higher brain areas implicated in color processing include the parvocellular pathway of the lateral geniculate nucleus of the thalamus, and visual area V4 of the visual cortex. Acquired color blindness is generally unlike the more typical genetic disorders. For example, it is possible to acquire color blindness only in a portion of the visual field but maintain normal color vision elsewhere. Some forms of acquired color blindness are reversible. Transient color blindness also occurs (very rarely) in the aura of some migraine sufferers.

Classification of color deficiencies
Acquired
Congenital
Dichromacy
Protanopia
Deuteranopia
Tritanopia
Anomalous trichromacy
Protanomaly
Deuteranomaly
Tritanomaly
Monochromacy
Rod monochromacy
Achromatopsia

Diagnosis
The Ishihara color test, which consists of a series of pictures of colored spots, is the test most often used to diagnose red-green color deficiencies. A figure (usually one or more Arabic digits) is embedded in the picture as a number of spots in a slightly different color, and can be seen with normal color vision, but not with a particular color defect. The full set of tests has a variety of figure/background color combinations, and enable diagnosis of which particular visual defect is present. The anomaloscope, described above, is also used in diagnosing anomalous trichromacy.

However, the Ishihara color test is criticized for containing only numerals and thus not being useful for young children, who have not yet learned to use numerals. It is often stated that it is important to identify these problems as soon as possible and explain them to the children to prevent possible problems and psychological traumas. For this reason, alternative color vision tests were developed using only symbols (square, circle, car).

Most clinical tests are designed to be fast, simple, and effective at identifying broad categories of color blindness. In academic studies of color blindness, on the other hand, there is more interest in developing flexible tests ([1], for example) to collect thorough datasets, identify copunctal points, and measure just noticeable differences.

[edit]
Treatment and management
There is generally no treatment to cure color deficiencies, however, certain types of tinted filters and contact lenses may help an individual to distinguish different colors better. Additionally, software has been developed to assist those with visual color difficulties.

Answer 4

colour blindness is the visual defect resulting in the inability to distinguish colors. About 8% of men and 0.5% of women experience some difficulty in color perception. You can know more about it in answers.com. if u want to know more, click on this link. http://www.answers.com/topic/color-blindness