What is Color Blindness?
Color blindness is a condition in which a person cannot distinguish color properly. There are several variations of color blindness and each one relates back to a problem with the functionality of the cells inside the retina that deal with processing light sensitivity. The rod cells are activated by low light while the cone cells are activated by daylight.
The pigments inside each of the 3 cone cells react and respond differently as each absorbs light. Each pigment processes a different wavelength: short, medium and long. In a normal eye, this interaction and overlap between the cones, pigments and the amount of light each absorbs as the eye processes various images is what makes it possible to create the wide spectrum of color that most individuals are able to view.
Color blindness results when one or more of the 3 cone systems is not functioning properly or at all. Some affected individuals are unable to detect any color and the life they see is monochrome. It’s as if these individuals constantly view black and white movies. Called monochromacy, this is the rarest form of color defect. Dichromacy (red-green defects) of which there are 3 different types and anomalous trichromacy (blue-yellow) are more common.
Symptoms of Color Blindness
The main symptom of color blindness is an inability to distinguish and/or correctly identify colors, particularly reds and greens and blues and yellows.
Who is at risk?
In the majority of cases, color blindness is hereditary, something that runs in the family. However, color blindness can also develop as the result of damage to the optic nerve, the eye (specifically the retina) and even the brain. In a few instances, this eye condition has been traced back to chemical exposure including exposure to medicines and poisons.
Interestingly, color blindness is more prevalent in men than women. Age is also a factor in partial color blindness. As the eyes ages, the lens tends to become darker which translates into images taking on a darker hue.
Color blindness is very easy to detect with Pseudoisochromatic Plate tests. The plates contain colored dots, with the background dots being one color. Another dot color forms the image of a number. Someone with normal color vision will be able to distinguish the number whereas someone with a color defect cannot discern the pattern that has been created using the different colored dots.
Color blindness that is inherited cannot be ‘cured’ because pigments are lacking. In cases of acquired color blindness, vision may be corrected if the underlying problem can be treated.
Once the type of color blindness has been determined, an affected individual’s only option is to rely on visual aids to help ‘see’ better. Specially-tinted contact lenses or glasses can help compensate for the inability to distinguish certain colors, but cannot restore ‘normal’ color capacity.
Affected individuals are generally capable of developing their own methods for accommodating their eye condition, and with the help of others, they make modifications to their environments to ensure their safety.