This is a randomized, double-masked, placebo-controlled, dose-ranging, parallel-group, multi-center study designed to evaluate the safety and efficacy of GLK-321 in patients with Demodex blepharitis.

Inclusion Criteria:

• Signs of Demodex blepharitis in at least one eye
• Best Spectacle Corrected Visual Acuity (BSCVA) of 20/80 Snellen or better in each eye

Exclusion Criteria:

• Presence of eczema or dermatitis in the ocular region of either eye
• Use of lid hygiene products within 14 days of Screening
• Active ocular infection or inflammation, other than blepharitis, in either eye at Screening
• Women who are pregnant, planning a pregnancy, or nursing
• Have used an investigational drug or device within 30 days prior to Screening or concurrently enrolled in another investigational drug or device trial