There are several causes of blepharitis which may depend on the type of belpharitis that has been contracted.
There are two types of blepharitis:
- Anterior blepharitis, which affects the outside front edge of your eyelids (near or among your eyelashes). It may be caused by an infection by staphylococcus bacteria.
- Posterior blepharitis. This is also called Meibomian gland dysfunction (MGD). MGD is caused when something affects the inside rim of your eyelids, just behind your eyelashes, which contains your Meibomian glands. Your Meibomian glands produce part of your tears.
You may also got blepharitis as a complication of seborrhoeic dermatitis, which makes your skin inflamed or flaky. This can involve the scalp (when it is called dandruff), lashes, ears and eyebrows. Seborrhoeic dermatitis can cause both anterior blepharitis and MGD.
For more information on the types of blepharitis please visit the NHS Choices website
Causes of blepharitis in people over 50
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.