A periorbital hematoma, commonly called a black eye or a shiner, is bruising around the eye commonly due to an injury to the face rather than to the eye. The name refers to the dark-colored bruising which is the result of accumulated blood and fluid in the loose areolar tissue following a blow to the head. This blood tracks freely under the scalp producing a generalised swelling over the dome of the skull but cannot pass into either occipital or the temple regions because of the bony attachments of the occipitofrontalis muscle. But this fluid can, however, track forward into the eyelid because the occipitofrontalis muscle has no bony attachment anteriorly. This leads to formation of hematoma a few hours after the head injury or cranial operation. If injury is more extensive, potentially even a skull fracture, an apparent black eye can sometimes worsen and may require professional medical treatment before it will resolve. This is more likely if the area around both eyes has been injured or if there is a history of prior head injury or fracture around the eye. Though disfiguring, the vast majority of black eyes are not serious, require little or no treatment, and will resolve spontaneously within a week or two.