The human Eyeball is an organ that uses light rays and their colors to see objects. Light rays enter through the pupil and make their way back to the retina; in a perfect situation they come to rest one focal point and clear vision is achieved. (It works similar to a very simple camera but is made up of many parts. ) In a not so perfect situation, the light rays bend unparallel to each other and don’t come to rest at one focal point on the retina resulting in a need for (prescription eyeglasses) to achieve the visual acuity required to see objects clearly.
Anterior Chamber (aqueous humor) – space filled with a watery substance, thick in structure, and is between the cornea and the lens.
Ciliary Muscle – this muscle controls an eye's viewing objects accommodation at different distances. This muscle affects the zonular fibers that suspend the lens during accommodation by causing the lens shape to change to focus light rays.
Choroid – the vascular layer that lies between the sclera and the retina and is about 0.5 mm thick; this is also known as the choroid coat.
Conjunctiva – is the sclera’s anterior cover and is transparent, or clear mucous membrane whose purpose is to prevent the eye from drying out.
Cornea – the clear covering on the front part of the eye; it covers the pupil, iris, and anterior chamber.
Crystalline Lens – helps refract light being focused on the retina by changing shape. This action changes the focal distance causing the light rays to come to one focal point on the retina.
Fovea – is responsible for sharp central vision that’s necessary for watching television, viewing up close, such as reading, driving, or any other activity where detail is the primary importance of what is being viewed.
Hyaloid Canal – holds and carries the hyaloid artery.
Iris – is the ring around the eye’s pupil.
Optic Disc – lacks the light sensitive rods and cones causing a break in the visual field known as the blind spot.
Optic Nerve – is part of the central nervous system; it transmits vision information from the retina to the brain and is also known as the cranial nerve II.
Pupil – is a circular clear opening, the eye’s window to the world, and is located in the middle of the iris. The reason the pupil appears to be black is because most of the light coming in through the pupil is absorbed by the eye’s tissues inside.
Retina – is made up of millions of tiny light receptors, also known as photoreceptors, which are part of an extreme metabolic active layer of nerves.
Sclera – is a tough protective exterior shell of the eyeball. Its composition is a dense fibrous tissue that covers the majority (four-fifths) of the eyeball and it also provides a place for the muscles responsible for moving the eyeball to attach to.
Vitreous Humor – the clear gel substance that fills the space between the eyeball’s retina and the lens. Often it is referred to as the vitreous or the vitreous body.
Zonule of Zinn – also known as the suspensory ligament is a ring of fibrous strands connecting the crystalline lens and the ciliary body together.