camera-type eye

The camera-type eye includes the eyeball proper (cornea, lens, iris, retina, vitreous and aqueous humors, sclera, choroid) and accessory structures such as the eyelids (protecting and lubricating the surface), conjunctiva (mucous membrane lining), and lacrimal apparatus (tear production and drainage).

The cornea provides about 70% of the eye's refractive power, while the crystalline lens adds variable focusing through a process called accommodation. Ciliary muscles alter lens curvature to focus near or distant objects precisely on the photoreceptor-containing retina.

Camera-type eyes evolved independently multiple times (convergent evolution) and are found in vertebrates (mammals, birds, reptiles, fish), cephalopod mollusks (octopus, squid), and some annelid worms. The vertebrate and cephalopod versions, while anatomically similar, differ in retinal organization.