Plain English Meaning
Cones are the cells in the back of your eye that let you see fine detail and color, but only when there is enough light. In darkness, they stop working well, which is why colors fade and detail disappears at night.
Full Definition
Cones are one of two types of light-sensitive cells in the retina of the eye. They are concentrated in the central part of the retina (the fovea) and are responsible for sharp, detailed vision and color perception. Cones require relatively bright light to function and become ineffective in low-light conditions.
Context Anchor
Seen in night vision discussions when explaining why the eye works differently in daylight, cockpit lighting, and dark conditions.
Derivation
Named for their shape — these cells are tapered like tiny cones under a microscope, distinguishing them from the rod-shaped cells (rods) that handle low-light vision.