Distance of macula from optic disc is:
**Core Concept**
The macula is a highly specialized region of the retina responsible for central vision and fine detail perception. The distance between the macula and the optic disc is a critical anatomical measurement that helps in the diagnosis and management of various retinal disorders.
**Why the Correct Answer is Right**
The macula is located approximately 3-4 mm from the optic disc, a distance that is crucial for the proper functioning of the visual pathway. This distance allows for the optimal resolution of visual images and prevents the optic disc from interfering with the macula's function. The fovea, the central part of the macula, is actually located about 1.5 mm from the center of the optic disc.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not provide a specific measurement or range.
**Option B:** This option is incorrect because it is not a commonly accepted measurement for the distance between the macula and the optic disc.
**Option C:** This option is incorrect because it is not a precise measurement and does not reflect the actual anatomical distance between the macula and the optic disc.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that the distance between the macula and the optic disc can vary slightly in different individuals, but a general range of 3-4 mm is commonly accepted.
**Correct Answer: C. 4 mm.**