Dissection of the Eye

External Features

• Muscles:
  • Rectus Muscles:
    • Superior Rectus
    • Lateral Rectus
    • Medial Rectus
  • Superior Oblique Muscle
  • Inferior Rectus and Inferior Oblique (cut)
• Conjunctival Membrane: Cut through if remaining

Fibrous Layer

• Sclera (white part)
• Cornea (clear part, allows light through)

Dissection Steps

1. Cutting the Sclera:
   • Make a hole in the side of the sclera
   • Continue with a circular cut around the cornea
   • Open the eyeball like a book
2. Underside of Cornea:
   • Iris and portion of ciliary body remain attached
   • Lens and vitreous humor stay behind

Detailed Examination

• Cornea: Inspect and place back of the eye down
• Iris:
  • Use blunt probe to remove iris from sclera/cornea
  • Inspect features (color, muscle functions)
• Ciliary Body: View from behind
• Lens:
  • Tough in fixed eyeballs, delicate in fresh ones
• Vitreous Humor: Remove to reveal neural layer (retina)

Neural Layer (Retina)

• Photoreceptors: Sensitive to light
• Macula Lutea: Central collection of photoreceptors
• Fovea: Central point in the macula
• Optic Nerve: Exit point for axons and blood vessels
  • Creates a blind spot
• Tapetum Lucidum: Reflective layer present in many animals (not humans)

Structures Identified

• Cornea
• Iris
• Lens
• Vitreous Humor
• Retina
• Tapetum Lucidum (if present)