Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Glaucoma ?
    ### Response:
    Glaucoma is a group of diseases that can damage the eye's optic nerve and result in vision loss and blindness. While glaucoma can strike anyone, the risk is much greater for people over 60. How Glaucoma Develops  There are several different types of glaucoma.
    