"the properties of light" probably mean we won't have cameras as small as a speck of dust or a grain of sand. But a grain of rice is pretty big. Can you explain why you think that won't be possible?
You can shrink the lens and CCD down that far[0], but adding in a power source and data storage is likely to increase the size. Batteries are not tracking other improvements in technology. Additionally with a lens that small you're almost certainly going to want some form of image processing. You can move the problems of storage and process if you want to radiate or have a wire, but those introduce other concerns. Shrinking the entire package down to a grain of rice seems overly optimistic.
