Martin D K, Holden B A
Phys Med Biol. 1986 Jun;31(6):635-49. doi: 10.1088/0031-9155/31/6/005.
The hydrodynamic squeeze pressure in the fluid thin film beneath hydrogel contact lenses fitted onto an axisymmetric model eye were measured. These pressures were due to the contact lens relaxing after deformation by an applied force of similar magnitude to the human eyelid force. The distribution of pressure for contact lenses typically fitted to human eyes was negative with respect to atmospheric pressure at the corneal apex and became less negative at the corneo-scleral limbus. The force that the contact lens applied to the cornea was determined by integrating the pressure distribution from the corneal apex to the limbus. This force varied from 6.0 X 10(-4) N to -7.8 X 10(-1) N depending on the thickness, elastic modulus and bearing relationship of the contact lens. An expression was derived to determine the pressure developed beneath the annulus of the hydrogel contact lens overlapping the cornea, in terms of the measured force over the cornea beneath the contact lens and the chord diameters of the contact lens and cornea. It was found that the deformation of hydrogel contact lenses on the model eye did not follow a linear elastic shell theory.
测量了安装在轴对称模型眼上的水凝胶隐形眼镜下方流体薄膜中的流体动力挤压压力。这些压力是由于隐形眼镜在受到与人类眼睑力大小相似的外力作用而变形后松弛所致。通常适配于人类眼睛的隐形眼镜的压力分布在角膜顶点相对于大气压为负，并在角膜 - 巩膜缘处负值减小。通过对从角膜顶点到角膜缘的压力分布进行积分来确定隐形眼镜施加于角膜的力。该力根据隐形眼镜的厚度、弹性模量和承载关系在6.0×10⁻⁴ N至 -7.8×10⁻¹ N之间变化。根据在隐形眼镜下方角膜上测量的力以及隐形眼镜和角膜的弦直径，推导出了一个表达式，用于确定水凝胶隐形眼镜与角膜重叠的环带下方产生的压力。结果发现，模型眼上的水凝胶隐形眼镜的变形并不遵循线性弹性壳理论。
