超视力人眼模型的研究

Hyperacuity eye model

超视力人眼模型对充分发掘人眼视力达到"鹰视"具有重要意义。用Zernike多项式描述角膜前表面,用渐变折射率描述晶状体的折射率分布,同时考虑人眼视轴和光轴的夹角对成像的影响,利用光学设计软件Zemax建立了人眼超视力模型。将Zernike条纹矢高面应用到人眼模型中,能有效改变视轴方向(即5°视场)的成像质量,提高点扩散函数(PSF)值。采用晶状体渐变折射率符合人眼的实际解剖结构,可有效减小人眼像差。通过分析人眼极限分辨能力和人眼模型波像差,得出当空间频率为60周期/度时,该模型对目标高频细节感知的调制度可达到0.55。

The hyperacuity eye model is critical for making human eyesight like an eagle. The anterior cornea surface is described by Zernike polynomials, and the refractive index profile of the crystalline lens is described by the graded refractive index. The hyperacuity eye model is established by the optical design software Zemax, with the influence of the angle between optical axis and visual axis of human eye on imaging taken into account. To apply the rise surface of Zernike fringe to anterior cornea of the human eye model may improve the imaging quality in the direction of the visual axis （5°visual field in Zemax model） and increase the value of point spread function （PSF）. The aberration of human eye can be reduced by adopting the graded refractive index of the crystalline lens, which conforms with the anatomical structure of the human eye. By analyzing the resolution limits of the human eye and the wave aberration of the eye model, it is pointed out that the modulability of the human eye model for sensing the object＇s high-frequency details can reach 0. 55 when the spatial frequency is 60 period/degree.