These neurons are arranged in lobes and tracts that are more specialized than simple ganglia. The eye of the octopus is very similar to that of vertebrates in that it has a cornea, lens, iris and retina. It can also focus and form images. However, the octopus eye is different from that of vertebrates in that it focuses light by moving the lens closer and further away from the retina. The vertebrate eye focuses by changing the shape of the lens.
Octopi can perceive shape, color intensity and texture.
Another difference is that the eye of the octopus has NO blind spot since the nerve cells leave from the outside of the eyeball. The octopus also has a statocyst located next to the brain. The statocyst is used to detect changes in gravity and respond to acceleration. Try this experiment using an earthworm.