Demodex folliculorum

This is a type of mite that inhabits meybomian glands and might be an additional cause of dry eyes [Source]

"To kill the mite I was prescribed with Metronidazole ointment which makes my eyes sore when applied on the eye-lids" [Source]

"I think that the mites are probably responsible for the malfunction of the oil glands in your eyelids. I also had dry eyes before experimenting with various demodex treatments. This symptom has completely disappeared, so I guess my experiments may have been successful." [Source]