Characterization of Signs and Symptoms of Participants With and Without Meibomian Gland Dysfunction

Inclusion Criteria: -Participants characterized as with or without Meibomian Gland Dysfunction. Exclusion Criteria: * Lid heating therapy, therapeutic gland expression, or meibomian gland probing within 12 months of enrollment * Contact lens use in the 30 days prior to enrollment * Lid hygiene within 48 hours prior to enrollment * Use of eye makeup within 8 hours of enrollment * Eyelash growth-stimulating products within 30 days prior to enrollment * Use of systemic vitamins and/or systemic supplements containing omega 3 fatty acids within 60 days of enrollment * Use of systemic anti-histamines within 30 days prior to enrollment.