Blunt Injury

Any structure of the eye or surrounds can be affected by a direct blow from a blunt instrument eg fist or ball. 

Eyelids typically quickly become bruised and swollen (black eye) and the force may cause skin laceration. Oblique trauma to the lower lid may cause an avulsion-type injury which, because it usually occurs at the medial end, leads to rupture of the tear-duct apparatus. Without appropriate repair ectropion or lacrimal obstruction is likely.

Severe blunt trauma may be sufficient to cause a blow-out fracture of one or more of the walls of the orbit or rupture of the eyeball itself (scleral rupture)

Scratches to the cornea (corneal abrasions) are common are are sub-conjunctival haemorrhages.  

Injuries to structures within the eye include:

Release of blood within the anterior chamber (hyphaema) occurs due to damage to the iris blood vessels. The vision will often be impaired and a fluid-level of blood be visible obscuring the iris.

Damage to the iris causing enlargement or irregularity (pupil abnormalities)

Damage to the fluid drainage mechanism of the eye leading to raised intra-ocular pressure and glaucoma

Damage to the lens leading to cataract or lens dislocation.

Haemorrhage within the vitreous (vitreous haemorrhage).

Tears in the retina leading to retinal detachment.

Bruising and/or haemorrhage of the retina itself (commotio), usually causing a reduction in vision.

Damage to the optic nerve (optic neuropathy)

Action

Wherever there is a reduction in vision, double vision, bleeding or a visible abnormality of the eye the patient should be seen urgently in the eye emergency department. Simple black eye without other changes can generally be left to settle spontaneously

Rare causes include: