These may cause haemorrhage inside the eye, cataract, retinal detachment or even rupture of the eye (see also EYE, DISORDERS OF). Injuries from large blunt objects – for example, a squash ball – may also cause a ‘blow-out fracture’ of the orbital floor resulting in double vision. Surgical treatment may be required depending on the patient's specific problems.

Most chemical splashes cause conjunctivitis and superficial keratitis in the victim (see EYE, DISORDERS OF); both conditions get better spontaneously. Alkalis (caustics) are more likely to penetrate deeper into the eye and cause permanent damage, particularly to the cornea. Prompt irrigation is important. Further treatment may involve testing the pH of the tears, topical antibiotics and CORTICOSTEROIDS, and vitamin C (drops or tablets – see APPENDIX 5: VITAMINS), depending on the nature of the injury.

Loss of corneal epithelium (outermost layer). Almost any sort of injury to the eye may cause this. The affected eye is usually very painful. In the absence of other problems, the epithelium heals very rapidly – small defects may close within 24 hours. Treatment conventionally consists of antibiotic ointment and sometimes a pad over the injured eye.

Most foreign bodies which hit the eye are small and are found in the conjunctival sac or on the cornea; most are on the surface and can be easily removed. A few foreign bodies penetrate deeper and may cause infection, cataract, retinal detachment or haemorrhage within the eye. The foreign body is usually removed and the damage repaired; nevertheless the victim's sight may have been permanently affected. Particularly dangerous activities include hammering or chiselling on metal or stone, and people carrying out these activities (and others, such as hedge-cutting and grass-strimming) should wear protective goggles.