Blepharitis is a very common eye condition. It is an inflammatory condition of the edges of the eyelids and sometimes blockage of the meibomian glands in the eyelids.
The causes of blepharitis are not always known, however, there are some factors that are commonly associated with it.
Anterior blepharitis affects the front of the eyelid, where the eyelashes are attached. Anterior blepharitis is caused by a sensitivity to a substance produced by bacteria (staphylococcus) normally found on the skin. Some people are sensitive to this substance ( a bacterial toxin) which leads to inflammation.
Posterior blepharitis affects the inner eyelid (the part that makes contact with the eye). This part of the eyelid contains tiny glands (called meibomian glands) that make oil. This oil helps to keep the eyes moist and comfortable. In blepharitis, these glands become blocked and irritated which prevents them from keeping the eyes properly lubricated. This can make the eyes feel sore or gritty and can make you prone to developing cysts or chalazion (small lumps or swellings) in the lids.