What are Cones?

• A. Light sensitive cells that respond to color
• B. The hole that lets light into the eye
• C. The jellylike tissue behind the lens
• D. The function of the cornea

Answer: (A)

Cones are the light-sensitive cells in the retina that detect color. They work best in bright light and come in three types, each most responsive to different wavelengths corresponding roughly to blue, green, and red. The brain uses the signals from these cones together to interpret a wide range of colors, and cones are concentrated in the center of the retina (the fovea) to provide sharp, detailed color vision. This is why we perceive colors and can see fine detail in daylight.

The other parts mentioned have different roles: the opening that lets light in is the pupil, the jellylike tissue behind the lens is the vitreous humor, and the cornea is the clear front surface that helps bend light as it enters the eye.