Abstract
Natural tears serve three main functions: they maintain the metabolism of the ocular surface tissues, afford a smooth surface that allows regular light refraction, and lubricate the ocular surface to facilitate blinking. They also have other functions, such as specific and non-specific antimicrobial and buffer effects, etc. Natural tears have a complex composition, water being the major component (98–98.5%), as well as salts, hydrocarbons, proteins, and lipids. There are two types of tear components: structural and active. The structural components of tears are rather abundant, and are the basis of the three-layered architecture of the tear film (lipid, aqueous, and mucinic) because of their physical and chemical properties. The active components of tears are very scarce, and act as nutrients, antimicrobials, enzymes, messengers, inhibitors, etc. Some tear components may serve both types of functions.
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Murube, J., Paterson, A., Murube, E. (1998). Classification of Artificial Tears. In: Sullivan, D.A., Dartt, D.A., Meneray, M.A. (eds) Lacrimal Gland, Tear Film, and Dry Eye Syndromes 2. Advances in Experimental Medicine and Biology, vol 438. Springer, Boston, MA. https://doi.org/10.1007/978-1-4615-5359-5_99
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DOI: https://doi.org/10.1007/978-1-4615-5359-5_99
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