a lay term used by dog owners, with various meanings. Can be used to refer to a sagging of the lower eyelid that exposes palpebral conjunctiva; an ectropion. In veterinary medicine it has been applied to a protrusion of the nictitating membrane (third eyelid) which may occur with dehydration, a loss of mass behind the globe such as atrophy of temporal muscles, or in cats particularly with sympathetic stimulation or irritation. May be associated with enlargement and prolapse of the gland of the third eyelid, called cherry eye.
bilateral protrusion of the nictitating membranes.