Von Graefe's sign is the lagging of the upper eyelid on downward rotation of the eye, indicating exophthalmic goiter (Graves' disease).
[1] It is a dynamic sign, whereas lid lag is a static sign which may also be present in cicatricial eyelid retraction or congenital ptosis.
A pseudo Graefe's sign (pseudo lid lag) shows a similar lag, but is due to aberrant regeneration of fibres of the oculomotor nerve (III) into the elevator of the upper lid.
[3] A pseudo Graefe's sign is most commonly manifested in just one eye but can occasionally be observed in both.
The reason only one eye is affected is not yet clear.