Structures and formation methods of a light sensing device are provided. The light sensing device includes a semiconductor substrate and a light sensing region in the semiconductor substrate. The light sensing device also includes a filter element over the semiconductor substrate and aligned with the light sensing region. The filter element has a first portion and a second portion, and the first portion is between the second portion and the light sensing region. The light sensing device further includes a light shielding element over the semiconductor substrate and beside the first portion of the filter element. In addition, the light sensing device includes a dielectric element over the light shielding element and beside the second portion of the filter element. A top width of the light shielding element is greater than a bottom width of the dielectric element.