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Typically, the nose is either missing or replaced with a non-functioning nose in the form of a proboscis. Such a proboscis generally appears above the central eye, and is characteristic of a form of cyclopia called rhinencephaly or rhinocephaly.



Although cyclopia is very rare, several cyclopic human babies are preserved in medical museums (e.g. The Vrolik Museum, Amsterdam). There are also two known cases of children with Down Syndrome being born with one eye.



Some extreme cases of cyclopia have been documented in cats. In such cases, the nose and mouth fail to form, resulting in suffocation shortly after birth.



