The object (or particles) will always remain in the front of the eye. Some parents worry that it could get lost behind the eyeball. The space beyond the eyelids recedes ¼ inch (6 mm) and then stops. A foreign object that falls on the front of the eye cannot be lost behind the eyeball, but it can cause scratches on the cornea.
However, some types of foreign objects can cause infections or damage vision. For first-time contact lens wearers, a common concern is that a lens will come off and potentially move behind the eye and get stuck. While it's possible for a contact lens to stick to the surface of the eye, the good news is that there's simply no way for it to get lost or trapped in the back. The anatomy of the eye itself acts as a barrier, ensuring that the lens always remains on the surface, so you can recover it quickly and easily.
The eye often flashes small objects, such as eyelashes and sand, by blinking and tearing. DO NOT rub your eye if there is something in it. Wash your hands before examining your eye. In some cases, a person may be able to remove a small object, such as dust, sand, or an eyelash, from the eye.
However, small objects in the eye can sometimes leave a small, superficial scratch.