The smallest particle of dust or grit in the eye may cause great discomfort and pain; but often the natural watering of the eye that results is enough to wash the foreign body out, a process that can be encouraged by blinking several times. The eye should not be rubbed as this may cause the particle to scratch the surface of the eye. If the foreign body still remains, you should get the casualty to sit down, preferably in a good light, while you examine the eye to find the particle. Once you can see it, you may be able to remove it with the corner of a clean handkerchief. Continued, severe, pain after the removal of a foreign body may indicate corneal damage. In this case the eye should be examined by a general physician or an ophthalmologist. If the particle resists gentle attempts to dislodge it, it may be embedded in the eye; in these circumstances the casualty should be taken to a doctor for its removal. If possible, the casualty should keep both eyes shut during the journey; this may help to reduce eye movement, and so limit further damage.