These devices will have very poor image quality. It's not like making small lenses is hard; the properties of light mean that anything usable as a camera will be visible to the naked eye. Cameras can be small, but they cannot be arbitrarily small. Your "What then?" will never happen.
"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.
