eyelids open at birth In mouse, eyelids normally fuse about 5 days prior to birth and reopen about 19 days later. MP:0001302 MP:0001342 MPheno.ontology open eye lids open eyelids open eyes instead of closed at perinatal stage; failure of the upper and lower thin folds of skin and muscle that cover the exposed portion of the eye to fuse completely together during development and an individual is born with the eye(s) uncovered leading to degrees of injury and blindness abnormal eyelid morphology