Color blindness or color vision deficiency is the inability of a person to know the differences between some colors. Vision and the ability to differentiate between colors in the spectrum are extremely essential in order to meet day-to-day chores of life. Human eye contains two specialized kinds of photoreceptor cells namely rods and cones that actively participate in regulating these activities. Any abnormalities or errors in these cells can result in the individual being unable to identify colors, a medical condition better known as color blindness or color vision defect.
Color blindness in most of the individuals is always an inherited trait. Since men have one X chromosome and women two, men are more prone to be color blind than women. Thus when a man inherits the gene for the defect he becomes color blind whereas a women when she inherits a single gene for the peculiarity will not be prone to the color vision defect. The reason is that the good X chromosome will control the defective gene inherited. Thus for a women to inherit the deficiency she must acquire the defective trait from both her parents.
The second cause for the defective color vision is through disease. Cataract is one of the most common causes for this inherited genetic deficiency. Also retinal and optic nerve maladies will also result in the deficiency. Medications like digitalis taken for heart disease, quinine for malaria and alcohol also ensue in color blindness.
Color blindness does not mean that the affected individual can see only black and white, but it means that they cannot see or they have trouble in making out the difference between some colors. Test yourself with the help of this diagram.
The human retina has two kind of light cells. The rod cells that is active in a low light and the cone cells that are active in a normal day light. In a normal eye, there are three kinds of cones that contain different pigments. These pigments are activated when it absorbs the light. The absorption capacity of the cones differ, one is sensitive to a short wavelength, one to a medium wavelength and the other one to a long wavelength. The absorption capacity of these three systems covers much of the visible spectrum.
Symptoms vary from person to person, but may include: Trouble seeing colors and the brightness of colors in the usual way.Inability to tell the difference between shades of the same or similar colors. Often, the symptoms may be so mild that some persons do not know they are color blind. A parent may notice signs of color blindness when a child is learning his or her colors.
Conditions degenerate further, as an armed clique gains control over food deliveries, subjugating their fellow internees and exposing them to rape and deprivation. Faced with starvation, internees do battle and burn down the asylum, only to find that the army has abandoned the asylum, after which the protagonists join the throngs of nearly helpless blind people outside who wander the devastated city and fight one another to survive.
There is no known prevention for this illness. Regular eye check-ups can be done to prevent visual deterioration. Since this is a lifetime condition, early diagnosis is very important to learn ways to cope with the problem. There is still no cure available for this condition. Coping techniques such as precautions and proper care are also needed. Individuals with this type of condition are generally prohibited from driving and operating machineries. Finally, wearing dark glasses are beneficial for patients with achromatopsia. But in some cases, certain color blindness can progress to legal blindness and sometimes a person will totally become blind.
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