Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) familial exudative vitreoretinopathy ?
    ### Response:
    Familial exudative vitreoretinopathy is a hereditary disorder that can cause progressive vision loss. This condition affects the retina, the specialized light-sensitive tissue that lines the back of the eye. The disorder prevents blood vessels from forming at the edges of the retina, which reduces the blood supply to this tissue.
    