Foreign body sensations can range from mild to severe. They may be momentary, intermittent, or persistent. They may last for a short or long period of time.
The eyes do not always differentiate between one type of foreign body and another. Sometimes a foreign body may be in one eye, but the sensation is felt in the other eye.
The most common foreign body sensation happens when we get something in the eye. Everyone has had an eye lash in their eye, or a particle of dust. This type of foreign body usually floats in the tear film. It moves around in the eye during a blink or when the eye is moved.
Sometimes it is difficult to determine where the foreign body is – in the eye ball, in the eye lid, or in the tear film.
Where is It?
If the foreign body moves around, it is in the tear film.
If the foreign body is always felt in only one place, it is either in the eye or on the inner skin of the eye lid.
To determine if the foreign body is in the eye or under the eye lid, very gently pull the lid slightly away from the eye in the area where the foreign body is felt. If the foreign body is no longer felt, it is in the eye lid. If it is still felt, it is in the eye.
Conjunctivochalasis can masquerade as persistent or intermittent foreign body sensation, and is often missed. The sensation can be mild or severe. When it is severe, a person may be unable to function normally and they may think about taking out their eyes.
Blocked or plugged meibomian glands (meibomian gland dysfunction – MGD, or obstructive meibomian gland dysfunction o-MGD)) can feel like a foreign body, or even like an eye lash in the eye, because the glands are distended, swollen with meibum that does not flow out.
Many other conditions can cause foreign body sensations and pain. Concretions are calcium deposits that sometimes form under the eye lids. These are usually yellow. Bumps sometimes form on the underside of the eyelid.