The Human Eye

The human eye is the organ which gives us the sense of light allowing us to learn more about the surrounding world than any of the other five senses. We use our eyes in almost everything we do whether reading,working watching television ,writing a letter driving a car and countless other activities
The eye allows us to see and interpret the shapes, colors, and dimensions of objects in the world by processing the light they reflect of give off.

Aqueous humor clear watery fluid found in the anterior chamber of the eye; maintains pressure and nourishes the cornea and lens
Vitreous humor clear, jelly-like fluid found in the back portion of the eye: maintains shape of the eye and attaches to the retina
Blind spot small area of the retina where the optic nerve leaves the eye: any image falling here will not be seen
Ciliary muscles involuntary muscles that change the lens shape to allow focusing images of objects at different distances
Cornea
transparent tissue covering the front of the eye: does not have blood vessels; does have nerves
Cones
photoreceptors responsive to color and in bright conditions; used for fine detail
Rods
photoreceptors responsive in low light conditions; not useful for fine detail
Fovea
central part of the macula that provides sharpest vision; contains only cones
Iris
circular band of muscles that controls the size of the pupil. The pigmentation of the iris gives "color" to the eye. Blue eyes have the least amount of pigment; brown eyes have the most
Lens
transparent tissue that bends light passing through the eye: to focus light, the lens can change shape
Macula
small central area of the retina that provides vision for fine work and reading
Optic nerve bundle of over one million axons from ganglion cells that carry visual signals from the eye to the brain
Pupil
hole in the center of the eye where light passes through
Choroid
Thin tissue layer containing blood vessels, sandwiched between the sclera and retina; also,