Waveguide geodesic lenses are key basic components in guide wave optical devices. Since their focus characteristics are independent of the wavelengths and the moded of the guided waves. Geodesic lenses lend themselves extremely well to the integrated optical devices. In this paper, the effects of fabrication errors of geodesic lenses described by four improved analytical solutions are studied by numerical analysis. The relations between the changes of the focal length and the depth changes due to fabrication errors of these lenses are obtained and compared. Considering the use of geodesic lenses in integrated optical devices, the fabrication tolerances of these lenses are given.