Blepharitis is a condition that causes inflammation of the oil glands in the eyelids. The condition is a common cause of dry eyes. This disorder is commonly associated with skin or bacterial conditions. While it can be irritating, the condition does not cause permanent vision impairment. Blepharitis is normally defined by its location on the eyelid. Anterior blepharitis occurs on the outer edge of the eyelids while posterior blepharitis occurs on the inner edges of the lids.