# Overall power/focal length of an eye and corrective lens system

Hey. I got this question wrong and I don’t get the explanation. I know that to fix myopia you need a concave lens to diverge the light rays so that the eye lens converges them further back on the retina. I don’t understand why the answer says that overall focal length decreases. If the image focuses further back wouldn’t that mean the focal length has increased? And I know that concave lenses have negative powers but the explanation says adding a corrective lens increases the overall power. Shouldn’t adding a concave lens with a negative power decrease the overall power of the system? If someone could clear these up for me I would really appreciate it.