Color Vision

Color Blindness

Color blindness is not a form of blindness at all, but a deficiency in the way one sees colors. With this vision problem, you have difficulty distinguishing certain colors, such as blue and yellow or red and green.

Color blindness (or, more precisely, poor color vision) is an inherited disorder that affects men more often than women. According to Prevent Blindness America, it is estimated that 8% of men and less than 1% of women have color vision problems.

The most common form of color blindness is impaired vision of the colors red and green.

Much less often, a person may inherit a trait that reduces the ability to see shades of blue and yellow. This relative deficiency in the colors blue and yellow usually affects men and women equally.

Symptoms and signs of color blindness

Do you have difficulty differentiating between the colors blue or yellow, or red and green? Does it sometimes happen that a person informs you that the color you are looking at is not the color you think it is?

If so, these are primary signs that you have impaired color vision.

Contrary to popular belief, it is rare for a colorblind person to see only in shades of gray.

Most people considered “colorblind” can see colors, but some are perceived as discolored and easily confused with other colors, depending on the type of color vision impairment.

Observe more simulations than a person with impaired color vision may see.

If you develop color vision problems when you have usually been able to see a full range of colors, you should definitely see your doctor. Sudden or gradual loss of color vision may indicate a variety of underlying health problems, such as cataracts.

A color blindness test can help determine the type of color vision impairment you have.

What causes color blindness?

Color blindness occurs when light-sensitive cells in the retina do not respond adequately to variations in light wavelengths that allow people to see a variety of colors.

The photoreceptors in the retina are called rods and cones. Sticks are more abundant (there are approximately 100 million sticks in the human retina) and are more sensitive to light, but are unable to perceive colors.

The 6 or 7 million cones found in the human retina are responsible for color vision, and these photoreceptors are concentrated in the central area of the retina called the macula.

The center of the macula is called the fovea, and this tiny area (0.3 mm in diameter) contains the highest concentration of retinal cones and is responsible for our most accurate color vision.

Inherited forms of color blindness are usually related to deficiencies in certain types of cones or by the absolute absence of these.

In addition to differences in genetic composition, there are other causes of defects or loss of color vision, such as:

  • Parkinson’s disease (PD). Because Parkinson’s disease is a neurological disorder, light-sensitive nerve cells in the retina, where vision processing takes place, may be damaged and unable to function properly.
  • Cataracts. The clouding of the eye’s natural lens that occurs with cataracts “discolors” color vision, making it much less bright. Fortunately, cataract surgery can restore the brightness of color vision when the cloudy natural lens is removed and replaced with an artificial intraocular lens.
  • Tiagabine for epilepsy. An antiepileptic drug known as tiagabine has been shown to reduce color vision by approximately 41% in those taking it, although the effects do not appear to be permanent.
  • Leber’s hereditary optic neuropathy (LHON). Particularly prevalent among men, this type of inherited optic neuropathy can affect even carriers who do not have other symptoms but do have a degree of color blindness. Fundamentally, with this disorder, defects are noted in the colors red and green.
  • Kallman syndrome. This inherited condition leads to failures of the pituitary gland, which can lead to incomplete or unusual gender-related development, such as sexual organs. Color blindness may be a symptom of this disorder.

Color blindness can also occur when aging processes damage the cells of the retina. Injury or damage to the areas of the brain where vision processing takes place can also cause color vision deficiencies.

Treatment and strategies for color blindness

Gene therapy has cured color blindness in monkeys, according to the results of studies announced in September 2009 by researchers at the University of Washington and the University of Florida.

While early discoveries seem promising, gene therapy would not be considered for humans until the safety of treatments is proven.

Meanwhile, there is no cure for color blindness. However, some strategies to manage yourself can help you function better in a color-oriented world.

Most people can adapt to color vision deficiencies without major problems. But some professions, such as graphic design and occupations that require working with the various colors of electrical wires, depend on accurate color perception.

If you realize that you suffer from a deficiency in color vision early enough in life, you may be able to compensate by dedicating yourself to training in one of the many careers that do not depend on the ability to see a full range of colors.

Diagnosing color vision impairment can also prevent learning problems during school, particularly since many teaching materials rely heavily on color perception. If your child has impaired color vision, be sure to talk to his or her teachers about the disorder so they can plan lessons and presentations accordingly.