… One of the most baffling mysteries of multiple personality disorder is how alternate personalities can sometimes show very different biological characteristics from the host and from each other. Several personalities sharing one body may have different heart rates, blood pressures, body temperatures, pain tolerances, and eyesight abilities. Different alters may have unique reactions to medications. Sometimes a healthy host can have alternate personalities with allergies and even asthma. An alter’s blood glucose (sugar) may respond differently to insulin than the host’s. Since studies done on people with such dramatically different alters have been small, no conclusions can be drawn and the puzzle remains to be solved.
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That the same person could have verifiably different eyesight under different personalities is something I have a hard time believing. Anyone have a reference for this claim?