We reported the differences of central corneal thicknesses （CCT） between both eyes . In our study, CCTs were measured using three types of specular microscopes, ultrasound pachymeter , and rotating Scheimpflug camera . We found that the CCTs measured by various specular microscopes differed between the right and left eyes, but this discrepancy has not been seen with ultrasound pachymetry or the rotating Scheimpflug camera. Although the mechanism of this discrepancy was unknown, to avoid differences in CCTs in both eyes, the manufacturers may be recommended to calibrate the specular microscopic devices with human subjects rather than the model eye and be advised applying the different conversion coefficients for each right and left eye. Still further, we need to understand the characteristic of each device and utilize the result for the evaluation of diseases.