What are rod cells in the eyes primarily used for?

Rod cells in the eyes are primarily used for seeing in low light conditions. These photoreceptor cells are highly sensitive to dim light and enable night vision, which is essential for navigating in environments where brightness is minimal. Rod cells do not detect color; instead, they are responsible for black-and-white vision and are prevalent in the peripheral regions of the retina. This adaptability to low illumination makes them crucial for twilight or nighttime conditions.

In contrast, functions such as detecting color in bright light and focusing on detailed images are primarily managed by cone cells, which are less sensitive to light and are responsible for color vision in well-lit conditions. Peripheral vision is a result of multiple types of photoreceptors, but rod cells contribute significantly due to their distribution around the periphery of the retina, enhancing human ability to see movement and detect objects in low-light scenarios.