MICRO AND NANO LUBRICANT BEHAVIOR OF TEAR FILM AQUEOUS LAYER

Authors

  • B. Bojović University of Belgrade, Faculty of Mechanical Engineering, Mechanical Production Engineering Department, Kraljice Marije 16, 11120 Beograd
  • Đ. Koruga University of Belgrade, Faculty of Mechanical Engineering, NanoLab, Kraljice Marije 16, 11120 Beograd

DOI:

https://doi.org/10.7251/127

Abstract

Tears provide moisture and supply oxygen and other important nutrients to the cornea, mechanically trap and flush out foreign bodies and chemicals and keep the surface of cornea smooth and optically clear. Additionally, during blinking, tear film lubricates the friction area between lids and ocular surface. Tear film contains an aqueous layer that includes water, bacteriostatics, proteins and salt. Contact lens wearers often suffer from dry eyes. These changes in the tear film are caused by contact lens design, surface, material and applied solution for conditioning. In case of application of gas-permeable contact lens, the multi-factorial problem of tear film stability and therefore, maintaining of lubrication are main goals in the ongoing investigation. This paper focuses on applied research of the response of material’s surface roughness quality to retain tear film on the micro and nano-level by using a gliding-box method for lacunarity analysis. The topology of contact lens surface with tear film as the lubricant was studied from the point of view of the water as primary consistent in its bulk liquid form, as well as confined water film organized into layers in a nanometer-sized channel. Contact lens surface topology observed on micro and nano-scale indicates different lubrication behavior of aqueous tear layer. As opposed to bulk water as a disordered medium in micro scale that flows very readily, nano-water demonstrates the behavior effectively like some phases of liquid crystals.

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Published

2012-10-19