Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Cone-rod dystrophy ?
    ### Response:
    Cone-rod dystrophies (CRDs) are a group of inherited eye disorders that affect both the cone and rod cells of the retina (photosenstitive receptor cells). In contrast to rod-cone dystrophies, individuals experience deterioration of the cone cells more severely than the rod cells.
    