The exact cause of blepharitis isn’t clear all the time.
It may be associated with one or more factors, including:
- Seborrheic dermatitis — dandruff of the scalp and eyebrows
- A bacterial infection
- Clogged or malfunctioning oil glands in your eyelids
- Rosacea — a skin condition characterized by facial redness
- Allergies, including allergic reactions to eye medications, contact lens solutions or eye makeup
- Eyelash mites or lice
- Acne rosacea (a skin condition that causes redness of the face)
- Malfunctioning of the meibomian eyelid oil glands
Blepharitis is usually caused by an excess growth of bacteria normally found on the skin. In this case, the bacteria will cause scales, or dandruff-like particles, to form along the base of the eyelashes. It can also occur when there’s a blockage of the oil (meibomian) glands, and possibly even allergies.
Blepharitis is more common in people over 50, but it can develop at any age. As you get older, the glands in your eyelids that secrete part of your tears become blocked more easily. Your tears contain fewer lubricants and your eyes can feel gritty and dry, so seborrhoeic blepharitis and MGD tend to happen more in older people.