I know that the problem with near sightedness if that the image is formed before the retina, so to fix it you have to push the image back. But if a diverging lens has a negative focal length, which would make the image negative, wouldn't that put the image to the left of the diverging lens, and consequently make the object (since the image of the lens is the object of the eye) farther away from your eye? A farther object would cause an even shorter image distance and wouldn't that not be what you want?