Cone-rod dystrophy (CRD) may be a cluster of inherited eye disorder that have an effect on the sensitive cells of the tissue layer known as the cones and rods. Cone dystrophy is a result of destruction to the cone cells of retinas. Individuals with this condition experience vision loss over time because the cones and rods deteriorate with time. It refers to a series of familial retinal disorders with earlier or preponderantly cone impairment and synchronic or subsequent less severe cone and rod impairment.