A type of photoreceptor cells concentrated in the macula of the retina, responsible for color vision and fine detail perception. Cones are composed of inner and outer segments and divide into three types namely; red-sensing cones at 60%, green-sensing cones at 30%, and blue-sensing cones at 10%. Color blindness, photokeratitis, retinitis pigmentosa, and Usher syndrome are associated with cones.