A microlens structure and a method of fabrication thereof are provided. The method comprises forming a layer of microlens material over a substrate, which has photo-sensitive elements formed therein. The microlens material, which comprises a photo-resist material, is exposed in accordance with a desired pattern a plurality of times. The energy used with each exposure process is less than the energy required if a single exposure is used. Furthermore, the masks used for each exposure may differ. In an embodiment, the masks are varied so as to create a notch in the upper corner of the microlens.