A color deficiency is what most people mistakenly refer to as color blindness. Labeling an individual as color blind is inaccurate because overall a person’s eyes function properly. The individual is able to detect, focus on and process images. Except for the condition called monochromacy, an affected person is not blind to color.
An individual with a color defect has difficulty distinguishing hues. Such a problem stems from the specialized cell receptors in the eyes called cones. Three different cones contain pigments that absorb various amounts of light. Wavelengths determine the amount of pigmentation the cones absorb and the absorption determines how the eye detects and blends the primary colors of red, green, blue and yellow.
Types of color deficiency
The hereditary forms of color deficiency fall into 3 categories: monochromacy, dichromacy and anomalous trichromacy.
* Monochromacy means that a person is not capable of seeing any hue. It is the truest example of color blindness. An affected individual sees the world around him in black and white and shades of gray. This results from an absence or deficiency in the eye’s cone receptor.
* A person with dichromacy can distinguish hues so the defect is not quite as significant. Hues result as the eye’s receptors react to the various wavelengths they continually receive. There are 3 forms of dichromacy and the differences between each involve the colors that can be detected.
For example, protonopia and dueteranopia mean that a person has difficulty distinguishing red/green/yellow but can see blue and yellow. The defect referred to as tritanopia is opposite: blues and yellows cannot be distinguished however reds and greens can. This latter condition is rarer and those with tritanopia find it easier to adjust to the world around them.
* Those with anomalous trichromacy can distinguish hues, and can do this better than those with dichromacy. In fact some individuals are barely aware they have a color defect. The two categories of trichromacy include protanomaly and deuteranomaly.
The only type of color defect that is not hereditary is tritanomaly.
Living with a Color Defect
The majority of individuals affected by a color defect are affected from the moment they are born. Early detection is crucial so that accommodations can be made to ensure that impacts to a child’s learning and development, in particular his perception of color, are limited. Adults with color defects find that some career paths are unattainable.
A color defect cannot be ‘cured’ therefore lifestyle modifications are necessary. Individuals learn to cope in a color-coded world by learning which colors belong where. A color deficiency doesn’t prevent a person from operating a motor vehicle, however, an affected individual needs to learn and recognize roadways signs and their respective meanings. For example, he must memorize that the light at the top of traffic signal is always red, that green is on bottom and yellow is in the middle.
Those with a color deficiency can benefit from having others help rearrange and organize their clothing. Doing so can eliminate the sometimes embarrassing situation of wearing mismatched colors of clothing.