After the photosensitive cell region invaginated, there came a point when reducing the width of the light opening became more efficient at increasing visual resolution than continued deepening of the cup. By reducing the size of the opening, organisms achieved true imaging, allowing for fine directional sensing and even some shape-sensing. Eyes of this nature are currently found in the nautilus. Lacking a cornea or lens, they provide poor resolution and dim imaging, but are still, for the purpose of vision, a major improvement over the early eyepatches.