本篇文章主要探討生物系統中眼睛角膜與隱形眼鏡之間的彈液動潤滑分析，由於在配戴隱形眼鏡時，透過上眼瞼的眨眼過程，鏡片會與眼睛表面的角膜組織產生滑動接觸的行為，而接觸表面之間會有淚液作為覆蓋薄膜，以防止鏡片與眼球表面直接接觸而造成眼睛角膜受傷而發炎，進而影響視力的正常功能，而此機制類似機械的滑動軸承。
由於生物軟組織具有非等向性和不可壓縮性的材料特性，本文這裡探討特殊形式的非等向性：橫向等向性角膜模型(xy平面具有相同的楊氏模數，而z方向的楊氏模數與xy平面不同)，針對幾個可能會影響眼睛舒適度的參數進行探討，如隱形眼鏡的材質、鏡片與眼睛角膜表面的相對滑動速度、眼瞼施予鏡片的外部負載和鏡片的曲率半徑等，基於彈液動潤滑理論：如Hertz接觸理論、雷諾方程式、線性彈性方程式和負載平衡方程式，透過有限元素法來計算出兩表面之間液膜所承受的壓力分佈、液膜厚度、鏡片與眼球的彈性變形量、摩擦力和摩擦係數等，由模擬結果我們可以知道，當配戴PMMA隱形眼鏡時，會使眼睛角膜表面的壓力分佈較配戴HEMA隱形眼鏡要來的大且集中，液膜厚度受到較大壓力滑動擠壓而變得較薄。根據鏡片與角膜表面之間滑動速度、外部負載和鏡片曲率半徑的不同，都會造成眼睛表面產生不同的壓力、液膜厚度和彈性變形。藉由本文分析所得到的結果，以供日後提供眼科醫師、視光師和隱形眼睛設計師作為重要參考的依據。

This article focuses on the elastohydrodynamic lubrication at cornea and contact lenses in biological system. When human wear contact lens, the upper eyelid will blink. In this process, the contact lens will contact with ocular surface, then the contact area will cover by the tear film which can prevent our cornea from being hurt by the direct contact with the contact lens, in order to protect our visual acuity. This mechanism is similar to the mechanical sliding bearings.
According to anisotropic and incompressibility of the soft biological tissues, we discuss the special forms of anisotropic which transversely isotropic cornea model is included. In this model we have the same Young’s modulus in the xy plane but different in z. We discuss some reasons that may impact the comfort of our eyes, such as the lens material, the sliding velocity between cornea and contact lens, the load from the eyelid to the contact lens or the curvature radius of the contact lens and so on. Based on the elastohydrodynamic lubrication theory including Hertz contact theory, Reynolds equation, linear elasticity equation and the load balance equation. We can calculate some data through the finite element methods like the pressure distribution on the liquid film between two surfaces, the thickness of the liquid film, the elastic deformation of the lens and the ocular, friction and the friction coefficient. From our simulation, we know that when we wear the lens, the pressure distribution on PMMA is bigger and more centralized than on HEMA and then the liquid will be thinner because of the greater sliding. The reasons that cause the change on the ocular surface pressure distribution and the deformation are the sliding velocity between the lens and the cornea, different external load and curvature radius. These results can give ophthalmologists, optometrists and contact lens designers some references in the future.

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