水晶体内の屈折率分布, 波長分散及びその温度変化について

Abstract

Purpose : To analyze the change of the refractive index distribution, and Abbe number of the lens near body temperature, and investigate their effects on the refraction of the eye. Methods : The materials were crystalline lenses extracted from ten pig eyes. The refractive index, chromatic dispersion, and Abbe number were measured at 36±3℃ with the Abbe's refractometer. Results : The refractive index was the highest in the lens core (nD=1.4236) and significantly low in the peripheral cortex (nD=1.3881) (p=0.0001). The temperature had no effect on the refractive index of the lens core(p=0.9404), but at the peripheral cortex this index increased with the increase in temperature (p=0.0107). The chromatic dispersion decreased in the peripheral cortex with the increase in temperature (p=0.0281). Although the mean value of Abbe number of the lens ranged from 28 to 42, the regional differences were not clear (p=0.0803). With the change of temperature, there were regional differ- ences in Abbe number of the various parts of the lens ; this index tended to increase with the increase in temperature in the peripheral cortex. Conclusion : The refractive index of the lens was found to be high in the lens core and low in the peripheral cortex. The chromatic dispersion as well as Abbe number in the inner part of the lens were not constant, but clearly showed topographic distribution. Moreover, their optical characteristics also showed temperature dependency.