38.1 Introduction to the Eyes

The eye is a complex organ with several key structures working together to enable vision. From the pupil and iris regulating light entry to the retina converting light into electrical signals, each part plays a crucial role in visual processing.

Common eye disorders like glaucoma and conjunctivitis can significantly impact vision and eye health. Understanding their causes, symptoms, and proper medication administration techniques is essential for effective treatment and management of these conditions.

Anatomy and Physiology of the Eye

Pupil, iris, retina

Top images from around the web for Pupil, iris, retina

• 

  Pupillary light reflex - wikidoc View original

  Is this image relevant?

• 

  Vision | Anatomy and Physiology I View original

  Is this image relevant?

• 

  Anatomy of the Eye | Biology for Majors II View original

  Is this image relevant?

• 

  Pupillary light reflex - wikidoc View original

  Is this image relevant?

• 

  Vision | Anatomy and Physiology I View original

  Is this image relevant?

1 of 3

Top images from around the web for Pupil, iris, retina

• 

  Pupillary light reflex - wikidoc View original

  Is this image relevant?

• 

  Vision | Anatomy and Physiology I View original

  Is this image relevant?

• 

  Anatomy of the Eye | Biology for Majors II View original

  Is this image relevant?

• 

  Pupillary light reflex - wikidoc View original

  Is this image relevant?

• 

  Vision | Anatomy and Physiology I View original

  Is this image relevant?

1 of 3

• Pupil allows light to enter the eye, size controlled by iris muscles
• Iris is colored part surrounding pupil, contains muscles regulating light entering eye
• Retina is light-sensitive layer at back of eye, contains photoreceptor cells (rods for low-light and peripheral vision, cones for color vision and visual acuity) converting light into electrical signals
• Cornea is clear, protective outer layer helping focus light
• Lens is transparent structure behind iris focusing light onto retina
• Optic nerve carries electrical signals from retina to brain for visual processing

Common Eye Disorders

Glaucoma, conjunctivitis causes and symptoms

• Glaucoma caused by increased intraocular pressure due to impaired drainage of aqueous humor, risk factors include age, family history, and certain medical conditions
  • Symptoms are gradual loss of peripheral vision, tunnel vision in advanced stages, pain and redness in acute angle-closure glaucoma
• Conjunctivitis (pink eye) caused by viral or bacterial infection, allergies or irritants
  • Symptoms are redness and swelling of conjunctiva (white part of eye), itching, burning, or gritty sensation in eye, discharge (watery, mucus, or pus)

Medication Administration Techniques

Eye drops, ointments proper techniques

• Eye drops
  • Wash hands thoroughly before administration
  • Tilt patient's head back and have them look up
  • Gently pull down lower eyelid creating a pocket
  • Hold dropper close to eye without touching surface
  • Instill prescribed number of drops into pocket
  • Have patient close eye and apply gentle pressure on inner corner preventing systemic absorption
• Eye ointments
  • Wash hands thoroughly before administration
  • Tilt patient's head back and have them look up
  • Gently pull down lower eyelid creating a pocket
  • Apply thin strip of ointment (about 1 cm) along inside of lower eyelid
  • Have patient close eye and gently massage eyelid distributing ointment evenly
• General tips
  • Use separate tube or dropper for each eye preventing cross-contamination
  • Wait at least 5 minutes between administering different eye medications
  • Educate patient on proper storage and handling of eye medications