Eye Structure and Function

Eye Structure

• The eye is a complex and highly specialized sense organ that detects light and converts it into electrical signals that are transmitted to the brain.
• The eye consists of several layers:
  • Cornea: transparent outer layer that bends light
  • Iris: colored part of the eye that controls amount of light entering the eye
  • Lens: flexible structure behind the iris that changes shape to focus light
  • Retina: innermost layer that senses light and sends signals to the brain
  • Sclera: white, tough outer layer that protects the eye

Eye Functions

• Vision: the eye converts light into electrical signals that are transmitted to the brain, allowing us to see and interpret visual information
• Focus: the eye changes the shape of the lens to focus on objects at different distances
• Movement: the eye moves to track objects and maintain focus
• Protection: the eye has several mechanisms to protect itself, including the eyelids, tears, and cornea

Types of Vision

• Central vision: sharp, detailed vision that occurs in the center of the visual field
• Peripheral vision: broader, less detailed vision that occurs on the periphery of the visual field
• Color vision: the ability to see different wavelengths of light as different colors
• Depth perception: the ability to perceive the distance of objects from the observer

Eye Disorders and Diseases

• Myopia (nearsightedness): a condition where close objects are seen clearly, but distant objects are blurry
• Hyperopia (farsightedness): a condition where distant objects are seen clearly, but close objects are blurry
• Cataracts: a clouding of the lens that affects vision
• Glaucoma: a condition where pressure in the eye damages the optic nerve
• Conjunctivitis (pink eye): an infection of the conjunctiva, the thin membrane covering the white part of the eye