There is provided an optical apparatus including a substrate, a light emitting device, a light sensitive device and a plurality of micro-lenses. The light emitting device is disposed on the substrate and adapted to provide a light beam. The light sensitive device is disposed on the substrate and adapted to receive a light beam reflected from an object, wherein the light sensitive device has a plurality of photosensitive units arranged in matrix. The micro-lenses are disposed above the light sensitive device and respectively opposite to the associated photosensitive units. There is further provided a light sensitive device with micro-lens and a manufacturing method thereof.