Blepharitis is caused by several different things which include skin conditions such as seborrheic dermatitis and rosacea, blocked eyelid oil glands and even bacterial overgrowth.
Even mites or Demodex and allergies can also result in and cause blepharitis.
Blocked eyelid oil glands and bacterial overgrowth are the most common causes of blepharitis.
The eyelids have tiny oil glands which are called the meibomian glands and these tiny oil glands in they eyelids secrete oil to lubricate your eyes.
But when the tiny eyelid oil glands get clogged or malfunction and not work as they should, they can lead to dry eye symptoms and posterior blepharitis.
The dysfunction of the eyelid oil glands is often associated with seborrheic dermatitis or rosacea.
Bacterial overgrowth can result especially when the oil glands are clogged but can occur at other times as well even when your eyelids are not cleaned.
Bacteria naturally live on the human skin, which includes around your eyelashes and eyelids and in blepharitis, there's an overgrowth of the bacteria, which is often the bacteria called Staphylococcus, which can result in irritation and inflammation of the eyelids.
The overgrowth of the bacteria can be caused by poor eyelid hygiene, underlying skin conditions and clogged oil glands.
Seborrheic dermatitis can result in dandruff on your scalp and eyebrows, which can spread to your eyelids and cause inflammation and result in anterior blepharitis.
Rosacea is a skin condition which causes redness and inflammation on your face, including your eyelids which can result in blepharitis forming.
Other things that can trigger or cause blepharitis are allergic reactions to makeup, contact lens solutions, other allergens, poor eyelid hygiene and demodex mites.
Demodex mites are microscopic mites which live in hair follicles including the hair follicles of the eyelashes and an overpopulation of Demodex mites can irritate your eyelids and cause blepharitis to form.