
Blepharitis a generic term for an inflammation of the edge of the eyelids. There are two categories of Blepharitis.
Anterior blepharitis has 2 causes: by an overgrowth of the normal skin flora (bacteria), or a seborrhic oily/greasy skin.
In the first type, bacteria, while growing at the opening of the oil glands (sebaceous glands of Zeiss) on the edge of the lid, excrete an exotoxin into the tears that cause the eyes to become irritated.
In the seborrhic form, there are flakes and crusts in the lashes, these cause ulcers at the lid edge.
In Posterior Blepharitis, the meibomian oil glands become blocked (this is called MGD or Meibomian Gland Dysfunction), keeping essential oils from lubricating the eye. There is also an engorgement of the blood vessels on the lid margin.
Redness of the eyelids, especially the edge
Swelling and tenderness of the eyelids
Itching around the lashes
Greasy flakes or scales around the lashes
Hard crusts at the base of the lashes, especially upon waking