The flatter concave lens becomes the emergent ray moves towards being parallel two incident rays.
Explanation-
A concave lens is a lens that diverges the rays, passing through the lens, from its path thereby appearing to come from a point where image is formed these types of lenses are used by people who find trouble in seeing things that are at a distance. The flatter the lens become it moves more towards becoming a glass slab which refracts the light such that the emergent ray is parallel two incident Ray but only from another point.