Wedge-Tailed eagle retina

The Wedge-tailed eagle's retina has about 1 million rod and cone cells in 1 square millimeter of their retina. That's five times the human eye's amount of rods and cones in the same area.

Since the eagle has a pecten, it thus supplies nutrients and oxygen to the vitreous humor, thereby reducing the number of blood vessels. With fewer blood vessels in the retina to scatter light coming in the eye, eagle eyes have evolved into having the best vision of all organisms. 

To move an image across the retina, the wedge-tailed eagle must move its neck side to side because it can't move its eyeballs freely. The deep dimple of the foveal surface acts as a negative lens (telephoto component). That means that the telephoto component magnifies the image of the prey in the wedged-tailed eagle's retina and as a result, the eagle can swoop it's prey even if it's very far.

Furthermore, an eagle’s eye has approximately five times the number of light-receptor cells that we have. Practically each receptor is connected to a neuron. As a result, the eagle’s optic nerve, which carries messages from the eye to the brain, contains double the number of fibers found in that of a human.

Rather than having an equal amount of rods and cones in its retina, the wedge-tailed eagle had more cones than rods, so it sees best in the daytime. That's why wedged-tail eagles hunt most of their prey during the day. If it were to have more rods, the vision at night would have improved.