Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) microphthalmia ?
    ### Response:
    Microphthalmia is an eye abnormality that arises before birth. In this condition, one or both eyeballs are abnormally small. In some affected individuals, the eyeball may appear to be completely missing; however, even in these cases some remaining eye tissue is generally present.
    