Red-Green color blindness is the most common type of the inherited color blindness disorders and consists of 3 main types: protanomaly, deuteranomaly and deuteranopia. According to the National Eye Institute this disorder affects approximately 6% of males while being much less prevalent in women, at less than 1%. According to Business Insider, the reason this disorder impacts men more than women is due to gender genetics. Specific defects within the x chromosome causes Red-Green color blindness and potentially along with other types of color blindness. In order for these defects to result in the expression of color blindness all x chromosomes have to be affected. In the case of males, who naturally only have a single X chromosome, only that chromosome needs to be impacted whereas women require both of their chromosomes to be effected. What specifically causes red-green color blindness? How does each type of disorder affect the afflicted?  How is it treated? Let's discuss these questions.

The National Institute of Health states that the medical explanation behind the causes of Red-Green color blindness is that it is due to a loss or limited ability to process red or green colors by the photopigment cells within the red or green color photoreceptor cones located within the retina. This loss or limitation prevents or diminishes the eye's ability to properly process color light signals therefore making it difficult for the individual to differentiate between certain colors. As mentioned above this disorder has various types. Let's review these next.

Protanomaly

Protanomaly occurs when the long-wavelength cones or L-cones are defective or completely missing. Therefore, with only two functional cone types remaining, one for short wavelengths and the other for medium wavelengths,  an individual's vision will be less sensitive to red light. This lack of sensitivity to red light not only impacts an individual’s ability to see the color red properly but any shades of it. Below is an example of how an individual suffering from protanopia may view colors compared to normal vision.

Deuteranomaly

Deuteranomaly is the most common type of red-green color blindness, and by extension, the most common type of overall color blindness. This disorder occurs when there is a defect with the photoreceptor cones that process medium wavelength inhibiting green colors and any variation of it. The level of variation in the inhibition of the color green depends on the severity of the disorder. Below is an example of how deuteranomaly vision compares to normal vision.

Deuteranopia

Deuteranopia is an aggressive version of deuteranomaly where the ability to process medium wave lengths is completely missing preventing green colors and any variation of these from being seen properly. In fact, an individual afflicted with this disorder can only process 2 or 3 different hues compared to the 7 hues someone with normal vision can distinguish.

Although Red-Green color blindness is the most common type of color blindness there are some possible treatments available for individuals suffering from this disorder. For instance, by wearing special glasses or soft contact lenses that alter the filtering of the light's wavelengths it is possible to improve the eyes' ability to process these colors.

For more information on color blindness, its various types and to take a test to find out whether or not you may suffer from this disorder read Contact Lens King's article titled "Color Blindness".