An image sensor

The invention relates to an image sensor pixel structure comprising: a photosensitive region surrounded by a peripheral area arranged on the surface of a semiconductor substrate, a stack of several insulating layers having alternately different refractive indices and placed au above said peripheral zone, a microlens positioned at the top of the pixel so as to converge the light from the pixel to the photosensitive area, and a transparent block positioned substantially above the photosensitive region.