What are Tears?

Two main components are crucial in forming the tear film that coats the cornea and keeps your eyes feeling moist and comfortable.

 


  1. Outer Layer

Located on the outermost part of the tear film, the lipid layer stabilizes the tear film and helps prevent evaporation. When you have Meibomian Gland Dysfunction (the most common type of dry eye) your tear film has less oil, so your tears evaporate too quickly.1-5, 7, 8

  1. Muco-Aqueous Phase

The Aqueous Layer is the largest portion of your tear film, responsible for supplying the moisture your eyes need to be comfortable. If you have Aqueous Layer Deficiency, your eyes don’t produce enough of the watery component of tears, which makes it harder for your eyes to stay moist.1-4 This innermost layer consists of proteins called mucins that allow the Aqueous Layer to “stick” to the otherwise watertight cornea.1-3, 7
These layers are necessary to create an ideal tear film for moist, healthy eyes. If any layer becomes depleted or compromised in quality, the tear film cannot properly coat your eyes and dry spots can form. This causes your eyes to become dry, irritated and uncomfortable.2


All three layers are necessary to create an ideal tear film for moist, healthy eyes. If any layer becomes depleted or compromised in quality, the tear film cannot properly coat your eyes and dry spots can form. This causes your eyes to become dry, irritated and uncomfortable.2

SYSTANE®brand products are formulated for the temporary relief of burning and irritation due to dryness of the eye.

SYSTANE<sup>®</sup> is the #1 Doctor Recommended Brand for Dry Eye Symptom Relief

References:
  1. National Eye Institute. http://www.nih.gov/health/dryeye/factsaboutdryeye.pdf Pages 1,2. Accessed March 12, 2013.
  2. TFOS International Dry Eye Workshop (DEWS II). Ocular Surf. 2017 Jul; 15 (6): 269-650.
  3. 2007 Report of the International Dry Eye WorkShop (DEWS)http://www.tearfilm.org/dewsreport/pdfs/TOS-0502-DEWS-noads.pdf Pages 75. 87.
  4. The International Workshop on Meibomian Gland Dysfunction: Report of the Definition and Classification Subcommittee. http://www.iovs.org/content/52/4/1930.full.pdf Pages 1930, 1935.
  5. The International Workshop on Meibomian Gland Dysfunction: Report of the Subcommittee on Anatomy, Physiology, and Pathophysiology of the Meibomian Gland. http://www.tearfilm.org/dewsreport/pdfs/TOS-0502-DEWS-noAds.pdf Pages 1338, 1353.
  6. Holly F. Lemp, MA. Formation and rupture of the tear film. Exp Eye Res 1973; 15: 515-25.
  7. AJ Bron. Diagnosis of dry eye. Surv Ophthalmol 2001; 45 Suppl 2: S221-6.
  8. Craig J, Thompson. Importance of the lipid layer in human tear film stability and evaporation. Optom Vis Sci. 1997; 74: 8-13.