Color blindness Symptoms and Signs

COLOR BLINDNESS

  Color blindness is not a form of blindness at all, but a deficiency in the way you see color. With

this vision problem, you have difficulty distinguishing certain colors, such as red and green or

blue and yellow. Red-green color deficiency is the most common form of color blindness; a less

common form is blue-yellow color deficiency.


Color Blindness Symptoms and Signs

   Do you have a hard time distinguishing if colors are red and green, or blue and yellow? This is

the primary sign of this vision problem. Contrary to popular belief, it is rare that a color-blind

person would see only in neutral colors or shades of gray.

Why color is important in every aspect of our daily life.

     It is often used to highlight information, to draw attention, and to provide cues that enable

individuals to discriminate among stimuli. Despite the significant role that color has played in

the design of various promotional media, little attention has been paid to the genetic and the

acquired color deficiencies that may render the use of color an ineffective or distorted cue in

conveying meaning in information.

    When an individual is exposed to a message, it may or may not be perceived, just like the  

hundreds of messages each day that go unnoticed in the clutter of messages that bombard the

typical person. Perception includes a process of selective reception, in which information-

processing capacity is selectively allocated or not allocated to incoming information.

    Characteristics of the stimulus are thought to enhance the likelihood of the consumer to pay

attention. Such stimulus determinants include the size, color, intensity, contrast, position,

directionality, movement, isolation, novelty, and attractiveness of the message and its parts.

    When the individual is limited in some sensory capacity, however, the incoming information

is likely to be partially perceived, distorted, or not perceived at all. As a result, some information

may be left unprocessed, while other information may be processed more thoroughly, as capacity

is re-allocated to the most able resources.

  A good example, will be the case using highlighter, in my book when I study for instead I

would use (red) for terms and (blue) for definition of the term.

What Causes Color Blindness?

  Color blindness occurs when certain cells in the retina that normally respond to color do not

respond as they should. Usually, people with a color deficiency are born with it, and the problem

affects more men than it does women. Color blindness is caused by a common X-linked

recessive gene. This means that, if you're color-blind, your mother must either be color-blind, or

have normal vision but carry the color-deficient gene. Color-blind fathers pass the gene to their

daughters only, who will have normal color vision unless their mother also carries the color-

deficient gene. Aging or disease can also damage retinal cells, and in extreme cases can lead to

almost total color blindness

Diagnosing color-vision deficiency

  Diagnosing color-vision deficiency early may prevent learning problems during the school

years, since many learning materials rely heavily on color perception. If your child has a color

deficiency, be sure to speak with his or her teachers about it, so they can plan their lessons

accordingly. Some people use special lenses for color blindness, which are filters available in

either contact lens or eyeglass lens form. They are available from a limited number of eyecare

practitioners in the United States and other countries.

   You can also learn ways to work around your inability to pick out certain colors. For instance,

you might organize and label your clothing to avoid color clashes. :)Ask friends or family

members to help!:) And you might remember the order of things rather than their color (for

example, the red light is at the top of a traffic light).

About 13 million Americans have some kind of color deficiency

    Bill Cunerty, a college instructor in California, compares his life to watching The Wizard of

Oz. "The first half is in black and white," he said, "and the second half is in color."

Bill is color-deficient, or color-blind-he has difficulty seeing certain colors. Bill world gained

new hues recently when he began wearing lenses made by ColorMax Technologies Inc. of

Tustin, Calif. Color-deficient people have defective cones, receptors in the eyes that are sensitive

to color. One set of normal cones senses red, one set senses green, and one set senses yellow and

blue. In some color-deficient people, one set of cones doesn't work at all, making it impossible to

see one color. In most color-deficient people, however, certain cones function abnormally,

making it difficult to tell the difference between two colors usually red and green.

  The new lenses won't fix color blindness, but they will filter the light entering the eye. Such

filtering can help color-deficient people who have trouble telling the difference between two

colors. For example, a person who can't tell red from green could be prescribed ColorMax lenses

that block out most green light. Such lenses make green objects appear noticeably darker than

red objects.

What have researcher discover recently

There is enormous variation in the X-linked L/M (long/middle wavelength sensitive) gene array

underlying "normal" color vision in humans. This variability has been shown to underlie

individual variation in color matching behavior. Recently, red-green color blindness has also

been shown to be associated with distinctly different genotypes. This has opened the possibility

that there may be important phenotypic differences within classically defined groups of color

blind individuals. Here, adaptive optics retinal imaging has revealed a mechanism for producing

dichromatic color vision in which the expression of a mutant cone photo pigment gene leads to

the loss of the entire corresponding class of cone photoreceptor cells. Previously, the theory that

common forms of inherited color blindness could be caused by the loss of photoreceptor cells

had been discounted. We confirm that remarkably, this loss of one-third of the cones does not

impair any aspect of vision other than color.

Color Blindness Treatment
  
  Color blindness cannot be cured. However, if you have difficulty distinguishing colors, or

you've observed this difficulty in your child, see your eye care practitioner.

I  would like to credit those website, books and journals, and thank them helping me write these paper.
Web site:
www.ironicsans.com/images/ishi-middle.jpg
http://www.allaboutvision.com/
Book`s
- Show quoted text -Diagnosis of defective colour vision / Jennifer Birch.
by Birch, Jennifer.
- Show quoted text -
Oxford ; New York : Oxford University Press, 1993.
Call#: 617.759 BIRCH 1993
Series: Oxford medical publications
Description: 187 p. : ill. (some col.) ; 25 cm.
ISBN: 0192618709 (hbk.) :
0192623885 (pbk.) :
- Show quoted text -Coping with color-blindess / Odeda Rosenthal, Robert H. Phillips.
by Rosenthal, Odeda.
- Show quoted text -
Garden City Park, N.Y. : Avery Pub. Group, c1997.
Other Authors: Phillips, Robert H., 1948-
Added Title(s): Coping with color blindess
Call#: 617.759 ROSENTH 1997
Description: xii, 180 p. ; 23 cm.
Notes: Includes index.
ISBN: 0895297337 (pbk.) :
Dancing in the dark / Frances Lief Neer.
Main Author:Neer, Frances Lief, 1915-
Subject(s):Visually handicapped --United States --Life skills guides.
Blind --United States --Life skills guides.
Joseph Carroll, Maureen Neitz, Heidi Hofer, Jay Neitz, David R Williams. Proceedings of the National Academy of Sciences of the United States of America. Washington: Jun 1, 2004. Vol. 101, Iss. 22; pg. 8461

Journals, pro quest:
Accessible advertising for visually-disabled persons: The case of color-deficient consumers
Carol Kaufman-Scarborough. The Journal of Consumer Marketing. Santa Barbara: 2001. Vol. 18, Iss. 4/5; pg. 303, 16 pgs
New specs help color-blind
Anonymous. Current Science. Stamford: Apr 7, 2000. Vol. 85, Iss. 14; pg. CS6