Final answer:
Visual acuity decreases in areas farther from the macula lutea due to a higher density of rods, shared connections between multiple photoreceptor cells and a single RGC, and additional light absorption by retinal structures. The fovea offers the sharpest vision with a one-to-one photoreceptor to RGC ratio and minimal light absorption by other structures.
Step-by-step explanation:
Areas farther from the macula lutea, which is characterized by the dense concentration of photoreceptor cells known as cones at its exact center called the fovea, experience a significant drop in visual acuity. This decrease in sharpness of vision is due to several factors. Notably, the arrangement of photoreceptors changes, with rods becoming denser as one moves towards the periphery of the retina, and several photoreceptor cells sharing connections with a single retinal ganglion cell (RGC) through bipolar cells, unlike the one-to-one relationship found at the fovea. As a consequence, the accuracy of visual transduction is reduced in the peripheral retina compared to the fovea.
Furthermore, the fovea is free of supporting cells and blood vessels, allowing for the least amount of light absorption by other retinal structures and hence, creating the greatest visual sharpness. In contrast, in the periphery of the retina, light is absorbed by additional structures like axons, RGCs, bipolar cells, and retinal blood vessels before reaching the photoreceptors. This setup, along with the higher ratio of photoreceptors to RGCs, contributes to the blurry or less clear vision experienced when objects do not fall directly on the fovea.