In three-dimensional (3D) fluorescent microscopy image formation is often approximated as the convolution of the specimen function and the point spread function (PSF) -the impulse response of the microscope. Several methods have been developed for the inversion of the image formation operator. Different methods are based on different approximations to the process of image formation and recording. This talk presents an overview of the most-widely-used of the existing methods, their capabilities and limitations. Current and future research areas are also mentioned