Any material such as dust, sand or paint that gets into the eye is called a foreign body. Foreign bodies fall into two categories.
- Superficial foreign bodies: these stick to the front of the eye or get trapped under one of the eyelids, but do not enter the eye.
- Penetrating foreign bodies: these penetrate the outer layer of the eye (cornea or sclera) and enter the eye. These objects are usually travelling at high speed and are commonly made of metal.
Superficial foreign bodies are not usually serious.
A penetrating eye injury can be extremely serious – it may lead to blindness if not detected and treated promptly. Even if treated appropriately, it may cause loss of vision.