Iris - Controls the amount of light entering the eye by adjusting pupil size.

Lens - Adjusts shape to focus light on the retina for clear vision.

Eyelids - Protect the eye by keeping it moist and shielding it from foreign substances.

Sclera - Focuses light onto the retina by changing curvature.

Optic nerve - Provides nutrients to the eye's lens and cornea.

Retina - Contains photoreceptors that convert light into nerve signals.

Cornea - Protects the eye and helps focus light onto the retina.