The lens is a transparent, flexible structure that changes shape to adjust the focus of light onto the retina, allowing clear vision at different distances.

The iris is the colored part of the eye that surrounds the pupil. It contains muscles that control the size of the pupil, adjusting the amount of light entering the eye.

The retina is a thin layer of tissue at the back of the eye that contains specialized cells called photoreceptors (rods and cones) which detect light and convert it into electrical signals.

The cornea is the transparent, dome-shaped structure that covers the front of the eye. It helps to focus light onto the retina and protects the eye from external elements.

The optic nerve is a bundle of nerve fibers that transmits electrical signals from the retina to the brain, where they are interpreted as visual information.

The aqueous humor is a clear, watery fluid that fills the space between the cornea and the lens. It helps to maintain the shape of the eye and provides nutrients to the cornea and lens.

The lacrimal glands, located above the eyes, produce tears that lubricate the eye and help to protect it from infection.

The sclera is the tough, white outer layer of the eye that provides protection and shape. It is also known as the 'white of the eye'.

The pupil is the black circular opening in the center of the iris. It controls the amount of light entering the eye by changing size.

The vitreous humor is a jelly-like substance that fills the space between the lens and the retina. It helps to maintain the shape of the eye and provides nutrients to the retina.

The choroid is a layer of tissue located between the sclera and the retina. It contains blood vessels that supply nutrients to the eye and a dark pigment called melanin, which absorbs light and prevents it from reflecting off the back of the eye.

Rods and cones are specialized cells in the retina that are responsible for detecting light and converting it into electrical signals. Rods are more sensitive to low light conditions, while cones are responsible for color vision and high-acuity vision.

The central retinal artery is a blood vessel that carries oxygenated blood to the retina. It branches into smaller vessels that supply blood to different parts of the retina.

Macular degeneration is a disease that affects the macula, the central part of the retina responsible for sharp central vision. It is a leading cause of vision loss in older adults.

The ciliary body is a ring of tissue located behind the iris. It contains muscles that change the shape of the lens, allowing the eye to focus on objects at different distances.