Our Tear Film

Written By Dr. Joseph Munsell

The makeup of the tear film and its relationship to the ocular surface is a complex one that plays an integral role in our health. 

  • The most important  function of the tear film is to promote clear and crisp vision. The tears coat and make a smooth surface over the cornea which prevents fluctuations in vision regardless of the environment. This is key when clear vision can mean the difference in driving safely at night or getting into an accident. The tears also form a protective layer to protect the eye from foreign material and infections. 

  • Generally speaking the tear film may be broken down into 3 distinct layers although this is a simplistic view. 

  • The inner layer is made of mucins (a combination of proteins and carbohydrates). This layer helps bond the water layer to the surface of the cornea and hold it in place. Without this critical component the tears would slide off the eye as you can imagine when water is splashed onto a window. These mucins are produced from our goblet cells.

  • The second layer is the aqueous layer. This layer consists of water and various vitamins and minerals that play a key role in maintaining a healthy and functioning cornea. This layer is produced from our lacrimal gland.

  • The third layer is the lipid or oil layer. This component increases lubrication and prevents the evaporation of the tears. These lipids are produced from our meibomian glands that are located in the upper and lower eyelids and are expressed with each blink we make.

  • Normal tears are a complex integration of substance and form and when they don't function properly the consequences can be dire.

Dr. Joseph Munsell

Joseph (Joe) Munsell, O.D. is a Wyoming native and was born and raised in Casper. Dr. Munsell is a partner at Cheyenne Vision Clinic. He received his BS degree with honors at the University of Wyoming and his Doctorate of Optometry from Pacific University College of Optometry where he graduated Summa Cum Laude. Dr. Munsell is a Wyoming licensed optometrist with full accreditation and is DEA certified to prescribe oral and topical medications to treat eye diseases and infections. He is a member of he Wyoming Optometric Association, American Optometric Association, and the Optometric Society of Optometric Surgeons. His areas of interest are in ocular disease, myopia management, and optometric surgery. During school he was inducted into the Beta Sigma Kappa honor society and was named student of the year by the Greater Western Council of Optometry in 2016. Dr. Munsell was awarded the Wyoming optometric Association’s young Optometrist of the Year in 2022. Dr. Munsell is a proud member of the Cheyenne Rotary Club and is deeply involved in his community. In his free time he enjoys skiing and golfing with his wife Lauren and playing fetch with his golden retriever.

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