Stellwag's sign is a sign of infrequent or incomplete blinking associated with exophthalmos or Graves orbitopathy. It is accompanied by Dalrymple's sign, which is a retraction of the upper eyelids resulting in an apparent widening of the palpebral opening.
Stellwag's sign is named after Austrian ophthalmologist Karl Stellwag von Carion (1823-1904).
References
Stellwag's sign Wikipedia(Text) CC BY-SA