These are photoreceptor cells in the retina of the eye that are specialized for dim light vision. They are responsible for our ability to see in low illumination conditions and are crucial for peripheral vision and the detection of movement. Unlike other photoreceptors, they do not perceive color but are highly sensitive to light intensity. An example is the ability to navigate a dark room or detect a faint star in the night sky.
The existence and function of these cells are fundamental to understanding visual perception, particularly in scenarios where light levels are limited. Their discovery and study have significantly contributed to our knowledge of how the eye adapts to different lighting conditions and how the brain processes visual information from the environment. This understanding is important in fields like ophthalmology and cognitive psychology for diagnosing and treating vision impairments and for studying the neural basis of visual experience.