The need for microlenses with a wide range of focal lengths from 10μm to 100mm and with a diameter varying from 10μm to 1mm lead to the development of various techniques which are able to generate these lenses in a photoresist substrate. The existing techniques are reviewed and a new one proposed. In this technique a positive or negative photoresist layer is exposed to a tailored light intensity distribution. After development of the photoresist, its surface is identical to the spatial intensity light distribution. Photoresist with an index of refraction of n =1.6 in the visible spectrum, can be used as a lens.