Phenomenon in which all colors are seen as grey due to decreased sensitivity of cones is called
**Core Concept**
The phenomenon being described is related to the physiology of color vision, specifically the role of cone cells in the retina. Cone cells are responsible for detecting different wavelengths of light, which are perceived as colors. Decreased sensitivity of cones affects the ability to perceive colors, leading to a loss of color vision.
**Why the Correct Answer is Right**
In a condition known as cone monochromacy or achromatopsia, the cones are either absent or non-functional, leading to a decrease in sensitivity to light and colors. As a result, individuals with this condition see the world in shades of grey, as the brain is unable to process the different wavelengths of light. This is because the cones are responsible for detecting the specific wavelengths of light that correspond to different colors, and without them, the brain is unable to distinguish between colors.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to the phenomenon described, as it does not involve a decrease in cone sensitivity.
* **Option B:** This option is incorrect because it is not a recognized condition related to cone sensitivity and color vision.
* **Option C:** This option is not relevant to the phenomenon described, as it does not involve a decrease in cone sensitivity.
**Clinical Pearl / High-Yield Fact**
Cone monochromacy or achromatopsia is a rare condition that affects approximately 1 in 30,000 people. It is often inherited in an autosomal recessive pattern and can be associated with other systemic conditions.
**Correct Answer: C. Cone monochromacy or achromatopsia.**