Swelling and blue discoloration around the eye as a result of haemorrhage under the skin. The cause can be a blow to the eye, or a fracture in the facial region of the skull. The skin tissue around the eye is loose-textured, which can cause severe swelling, to the extent that the upper eyelid cannot be opened. If the skull is fractured, both eyes may be blackened. Fracture of the cheekbone or severe haemorrhage can cause double vision (diplopia), because the eye cannot be directed properly. A doctor should be consulted if fracture of the skull is suspected; X-rays may be necessary. Double vision should be treated by an ophthalmologist. It is advisable to place a cold compress on a black eye caused by a blow; the coldness reduces the swelling by narrowing the blood vessels in the affected area. The eye will turn green and then yellow after a few days, as subcutaneous blood is broken down.