Structure of the Eye

Sclera

• Definition: The white part of the eye.
• Function:
  • Protects the eye.
  • Serves as an attachment point for muscles.

Cornea

• Description: Transparent layer at the front of the eye.
• Function:
  • Protects the front of the eye.
  • Bends light slightly.
• Protection: Covered by the conjunctiva (thin layer of epithelial cells) to prevent friction and protect from dust and debris.

Aqueous Humour

• Location: Anterior chamber of the eye.
• Composition: Water and salt.
• Function: Fills the anterior chamber.

Lens

• Description: Bi-convex, capable of changing shape.
• Function: Further bends light.
• Ciliary Body:
  • Composed of ciliary muscles and suspensory ligaments.
  • Changes shape of the lens.
  • Secretes aqueous humour.

Underwater Vision

• Problem: Light bends differently underwater, causing blurriness.
• Solution: Goggles create an air layer, helping light bend correctly.

Iris and Pupil

• Iris:
  • Colored part of the eye (pigmentation).
  • Composed of muscles that adjust the size of the pupil.
• Pupil:
  • Hole whose size is controlled by the iris.
  • Adjusts for light intensity.

Vitreous Humour

• Location: Posterior chamber of the eye.
• Composition: Jelly-like substance.
• Function:
  • Suspends the lens.
  • Provides structure.

Retina

• Function: Contains photo receptors that convert light into neural impulses.
• Effect: Red-eye in photos due to light reflection.
• Optic Nerve: Fibers from the retina send visual information to the brain.

Choroid

• Description: Network of blood vessels.
• Function:
  • Nourishes retinal and other eye cells.
  • Pigmented black to absorb light.
• Comparison with Cats: Shiny choroid enhances night vision by reflecting light back to the retina.

Fovea and Macula

• Fovea:
  • Located within the macula.
  • Rich in cones for detailed vision.
• Macula: Anatomical region surrounding the fovea.

These elements collectively contribute to the eye's functionality, allowing it to process visual information effectively.