This is an exploratory study to evaluate endpoints used to characterize participants with and without meibomian gland dysfunction (MGD) and will evaluate the correlation between signs and symptoms of MGD. No investigational drug will be administered in this study.

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.

Participants characterized as with or without Meibomian Gland Dysfunction.