The “Rods” refers to the photoreceptor cells found in the retina of the eye that are primarily responsible for vision in low light conditions. Unlike cones, rods are more sensitive to light, but they do not detect color. They play a crucial role in night vision and peripheral vision.
Function of Rods
Rods are responsible for providing us with vision in dim light. They contain a pigment called rhodopsin, which undergoes a chemical change when exposed to light, initiating the signal transmission to the brain. This process allows us to perceive shapes and objects in low-light environments.
Anatomy of Rods
Rods are long and slender cells that are concentrated in the outer regions of the retina. They contain specialized structures called outer segments, which are packed with stacked membranous discs containing the rhodopsin pigment. These outer segments connect to the inner segments, which house the cell’s vital organelles.
Differences from Cones
Rods differ from cones, another type of photoreceptor cells in the retina, in several ways. While cones are responsible for color vision and work best in bright light conditions, rods are highly sensitive to low levels of light but do not perceive color. Rods also outnumber cones significantly in the human retina.