Ocular rosacea is an inflammatory disease of the eyelids and ocular surface. Like the facial disease, the ocular condition is chronic and recurrent. Sequelae of ocular rosacea vary from mild to severe. Ocular rosacea may cause chronic eye redness, blepharitis, recurrent chalazia, dry eye, corneal erosion, corneal vascularization, and corneal ulceration. Rosacea affecting the cornea can result in vision loss. Prescription eye drops and ointments can be used topically to control mild ocular rosacea. However, severe disease, or rosacea that is not well controlled with local treatments is treated systemically. The most commonly used systemic treatment for rosacea is the bacteriostatic antibiotic doxycycline. Rosacea treatment doses of doxycycline vary widely. Treatment-dose doxycycline for systemic infections is 100mg twice a day. However, as rosacea is considered an inflammatory disease, doxycycline is often dosed at what is termed, sub-microbial dose doxycycline (SDD). Initially introduced in the oral medicine literature, SDD are doses 40mg and lower because systemic administration at this dose does not appear to alter the oral mucosa flora or increase resistance rates when given long-term for periodontal disease. Whereas 100mg doxycycline, even when given short term, may increase the percentage of culturable nasopharyngeal flora that is resistant to doxycycline. The FDA does not categorize SDD an antibiotic, stating this dosing is expected to exhibit only anti-inflammatory activity.