Application #11: Eyes Copy

Lesson
Materials

Eyes

Anatomy:
Light passes through the front of the eye (cornea) to the lens. The cornea and the lens help to focus the light rays onto the back of the eye (retina). The cells in the retina absorb and convert the light to electrochemical impulses which are transferred along the optic nerve and then to the brain.

Innervation:
Six cranial nerves innervate motor, sensory, and autonomic structures in the eyes. The six cranial nerves are the optic nerve (CN II), oculomotor nerve (CN III), trochlear nerve (CN IV), trigeminal nerve (CN V), abducens nerve (CN VI), and facial nerve (CN VII).

Vasculature:
The eyeball receives arterial blood primarily via the ophthalmic artery. This is a branch of the internal carotid artery, arising immediately distal to the cavernous sinus. The ophthalmic artery gives rise to many branches, which supply different components of the eye.

Possible Effects of a Strike:
  • severe contusions of the eyeball
  • serious injury to the inner structure of the eyeball
  • vascular lesions leading to internal bleeding of the eye
  • increased eye pressure
  • tears in the iris
  • blurring of vision
  • displacement of the lens
  • swelling of the retina
  • damage to the optic nerve
  • reduced vision
  • sudden reduction in heart rate
  • loss of consciousness
  • cardiac arrest due to oculocardiac reflex (Aschner Phenomenon)
  • fracture of the orbital bone which can damage nerves and blood vessels
  • displacement of the eyeball
  • increased tearing leading to loss of vision
  • localized pain