Color blindness is a common vision condition, with red-green color blindness affecting an estimated 8% of men and 0.5% of women with North European ancestry. Though not inherently dangerous, color blindness can have a huge impact on the life of those who inherit it.
What is Color Blindness?
Color blindness refers to a decreased capacity or inability to see certain colors. There is no literal blindness, simply a difference in color perception. The three main kinds of color blindness are:
- Total color blindness, or monochromacy, is when an individual is not able to distinguish colors from each other. People with monochromacy see in black and white.
- Red-green color blindness results in an individual being unable to distinguish colors which have red or green in them. When this is very severe, reds appear black, purples and blues appear the same, and orange-reds can be mistaken for yellows. Less severe color blindness of this kind makes reds, greens, browns, and oranges difficult to distinguish.
- Blue-yellow color blindness is very rare. This kind of color blindness reduces colors primarily to reds, pinks, blacks, whites, greys, and turquoises.
For a feel for what the world looks like with color blindness, check out these examples on the Color Blindness Awareness site.
Who is Affected by Color Blindness?
Color blindness can either be inherited or acquired.
Inherited color blindness is a sex-linked genetic trait. In people with red-green color blindness, the L-cones or the M-cones are deficient. For people with the rare yellow-blue color blindness, there is a problem with their S-cones. Because color blindness is attached to the X chromosome, it is more likely that a male child will inherit color blindness than a female child. Color blindness may manifest in infancy, or develop in adolescence or adulthood.
Acquired color blindness is not as common as inherited color blindness. However, color blindness can result from Shaken Baby Syndrome, brain trauma affecting the occipital lobe, or exposure to ultraviolet light. It may also be caused by degenerative diseases such as diabetes, multiple sclerosis, or macular degeneration.
How is Color Blindness Diagnosed?
Color blindness can be diagnosed through an eye exam. Many eye exam testing centers, such as The Eyewear Place in Edmonton, offer the usual tests for visual clarity and binocular vision, as well as tests for color vision.
The Ishihara Color Test is the most common diagnosis tool used. Test subjects are shown plates like the one above. An individual with normal color vision will clearly see the number “74,” while individuals with color blindness may see the number “21,” or be unable to distinguish a number at all.
How Does Color Blindness Affect Everyday Life?
Color blindness can cause simple problems such as being unable to distinguish red apples from green apples (or a red traffic light from a green one), but most of these issues already have countermeasures in place. Apples, for example, are labelled and separated by type, and traffic lights can be identified by location rather than by color.
In some countries, such as Romania, individuals with color blindness cannot get driver’s licenses. Many color blind people are excluded from certain occupations where color differentiation is an essential part of the job description, such as some engineering fields, commercial painting, and many kinds of vehicle operation.
In some cases, color blindness can be counteracted through a colored glasses lens which can increase the ability to differentiate colors. Because color blindness also depends on the medium used in color presentation, some individuals with color blindness may find it easier to distinguish colors on a computer screen than on paper.
Color blindness is classified as a disability; however, this may be inaccurate. While color blindness can cause problems distinguishing color-coded objects, studies show that individuals with color blindness may actually be more adept at penetrating through color camouflage because their eyes are not drawn to contrasting colors.
While color deficiency often necessitates finding alternatives for certain systems, it in no way prevents an individual from functioning. Even in industries where color differentiation is essential, such as art, persevering individuals have succeeded in spite of color blindness.