<prompt> Horners syndrome is characterized by the following exceptPtosisMiosisHeterochromia iridisApparent exophthalmos  <response>: Common signs and symptoms include: A persistently small pupil miosis A notable difference in pupil size between the two eyes anisocoria Little or delayed opening dilation of the affected pupil in dim light. Drooping of the upper eyelid ptosis Slight elevation of the lower lid, sometimes called upside-down ptosis Ref ganongs review of medical physiology 25e p431 