This is called _hare-eye_ (lagos, hare) from the fact that the hare
habitually keeps the eyelids open. It is mostly due to spasm of the
levatores palpebræ, or to undue size of the orbicular opening. It may,
however, accompany ectropion, exophthalmos, and enlargement or swelling
of the eyeball from any cause. Bayer has seen cases in diseases of the
trifacial nerve, in neoplasms in the orbit and in buphthalmus.
Cases of the kind are especially liable to irritation, inflammation and
ulceration due to foreign bodies falling on the exposed bulb.
The _treatment_ is largely that of the attendant condition ectropion,
tumor, etc., which may be consulted.