The sclera can be seen above the cornea, and further upgaze increases the distance between the eyelids and irises.
Causes
Upper dorsal midbrain supranuclear lesions such as Parinaud's syndrome, 'top of the basilar syndrome', midbrain infarction, neurodegeneration or tumour, multiple sclerosis, encephalitis, and Miller-Fisher syndrome. Damage to the posterior commissure levator inhibitory fibres which originate in the M-group of neurons.
^J. Collier, Nuclear Ophthalmoplegia with special reference to retraction of the lids and ptosis and to lesions of the posterior commissure. Brain (journal) 1927; 50; 488 - 498.