Refractive index of the human lens surface measured with an optic fibre sensor

The refractive index of the human eye lens has been measured directly with a reflectometric, optic fibre sensor. Thirteen human lenses ranging in age from 27 to 84 years were examined. The results show that the refractive index is higher on the anterior than on the posterior surface with most of the values ranging from 1.364 to 1.381 and 1.338 to 1.357, respectively. There is no topographical variation along either surface and no evidence of age-related differences. Results using the sensor are compared with those from the Abbe refractometer on homogeneous materials. The refractive index of distilled water was found to be 1.332 with the fibre sensor and 1.3326 with the Abbe refractometer; of 0.5% agarose gel, it was 1.334 and 1.3355, respectively.