Week 8: Eyes and Ears

Question 1

Extraocular muscles of the eye

Answer 1

*Superior rectus
*Inferior rectus
* Lateral rectus
* Medial rectus
*Superior oblique
*Inferior oblique

Question 2

Visual reflexes

Answer 2

*Pupillary light reflexes
*Fixation
*Accommodation

Question 3

Developmental considerations for eyes in infants and children

Answer 3

• Peripheral vision is intact in newborn infant
• Macula, area of keenest vision, is absent at birth but mature by 8 months
• By 3 – 4 months of age, infant establishes binocularity and can fixate on a single image with both eyes simultaneously
• Lens is nearly spherical at birth, growing flatter throughout life

Question 4

Development considerations for eyes in older adults

Answer 4

• Pupil size decreases
• Lens loses elasticity, becoming hard and glasslike which
  decreases ability to change shape to accommodate for near
  vision; this condition is termed presbyopia
• By age 70, normally transparent fibers of lens begin to
  thicken and yellow, the beginning of cataracts
• Visual acuity may diminish gradually after age 50, and more
  so after age 70

Question 5

Use of ophthalmoscope

Answer 5

*Functions as appendage of examiner’s eye
– Illuminates the inner parts
* Contains set of lenses – unit of strength is diopter
– Positive diopters (black) focus on near objects
– Negative diopters (red) focus on objects farther away