Prior to 2002, the scientific community had only known about two types of photoreceptor cells in the retina - rods and cones - that specialize in converting light energy into electrical signals that ...

The eye has two kinds of photoreceptors that convert light into electrical activity: rods and cones. It is necessary to “divide the labor” between two cell types to enable the eye to see over ...

Rods and cones studding the retina can work in tandem to give an animal good vision in a wide variety of light conditions. Some species that live in dark environments, like many deep-sea fish ...