Color Blindness: The Basics

Color blindness is simply the impairment of the physical ability to see colors. In this case, there is a problem with the eye pigments responsible for color-sensing. This results in an inability to or difficulty in distinguishing colors. Most color blind folks cannot differentiate between green and red. Specifically, this is called daltonism. The least common instance of color blindness is the blue-yellow dichotomy.

There is always a degree to color blindness, i.e., it can be severe, it can be mild. The most severe form of this condition is called achromatopsia or achromatopia, and it is very uncommon. Here, the person can only see white, black or gray.

The under-listed colors are seen in color charts by most color blind people instead of green red or teal, seen by others.

  • Blue
  • Beige
  • Gray
  • Yellow

Sex wise, the rate of this condition is higher in men than in women. A woman might just carry the impaired chromosome that causes color blindness but is easier and commoner for a man to inherit it. In fact, just about 0.5% of women are color blind whereas the male takes as high as 8 percent.

Color blindness
Photo Credit: WebMD

Symptoms of color blindness

  • There is a change in vision, e.g. the inability to recognize the red or the green traffic sign.
  • Colors become less dim than they appeared before.
  • Confusion of different shades of a particular color for one color.

Note that color blindness is most obvious at childhood as a child is trying to learn colors. It might not be easily detected, in some cases, because a child might learn to associate a particular color with a particular item. Depending on how mild the condition is, one may not even realize his/her inability to recognize certain colors. If you are not sure, consult a doctor for anaccurate diagnosis.

Types of color blindness

Color blindness is majorly of 3 types.

  1. Achromatopsia: this is a condition whereby a person can only see the colors white, black or gray. Achromatopsia is very rare.
  2. There is a case where the person finds it difficult to distinguish between green and red.
  3. The last one is a condition whereby the person is unable to differentiate between blue and yellow.

There is still another level of classification of color blindness. This encompasses:

  1. Inherited color blindness: A person can be color blind as a result of a genetic defect. If you have a close family relative who is color blind, you may likely inherit the condition. This is the commonest type.
  2. Acquired color blindness: A person might develop color blindness at a later age due to diseases that damage the retina or optic nerves. There is a need to seek medical diagnosis at the first notice of visual changes as there might be a severe situation underneath.

Causes of color blindness

Basically, this condition happens when the cones in the retina are impaired or absent. The cone is a container for nerve cells in the retina, the retina being the layer of tissue at the back of the eye sensitive to light. The retina has 3 cones, each functioning to respond to the colors blue, green and red. The cones connect with the brain to identify each color. A malfunction of this system can result in color blindness. There are, however, factors responsible for such conditions. They are as listed below:

Heredity: Most people with color blindness inherited it, say from father to daughter. If color blindness is inherited, it is less likely to result in loss of vision.

Diseases: A disease can also make someone color blind. Such diseases include:

  • Glaucoma, which causes the optic nerve some damage due to a rise in intraocular pressure.
  • Diabetic retinopathy
  • Diabetes
  • Macular degeneration
  • Cataract
  • Multiple Sclerosis
  • Alzheimer’s disease
  • Parkinson’s disease

Medications: Some medications are capable of altering vision in human. These include antipsychotic drugs as well as an antibiotic used in treating tuberculosis, known to impair the optic nerve.

Other Factors: These may include age and toxic chemicals.

Diagnosis

During a regular eye checks, the doctor can examine your eyes for such a defect as color blindness. The examination is carried out using pseudo-isochromatic plates. These plates contain tiny symbols and numbers embedded in tiny colored dots and visible to only persons with good vision. A color blinded person might not see different numbers or may not even see the numbers and symbols at all.

It is advisable that a child from a family history with color blindness gets tested before starting school.

Color blindness in the long term

Sadly, no cure is available for inherited color blindness. Contact lenses or tinted glasses might be recommended to aid better vision.

In a case whereby this condition is caused by injury or disease, an improved vision can be obtained if the injury or disease is treated.

If you are unable to correct the condition and you wish to drive, you might have to memorize the order of signals from a traffic light. You might also consider labeling your cloths. In ICT, certain software programs read out colors or transform them in a way visually impaired people could read.

Whatever the case, find a way to adapt with the condition.

Leave a Reply