CH 15 Eyes

Question 1

Structure + Function of Eyes

Answer 1

External Anatomy
- eyelashes/eyelid: protection
- cornea: cover/protect iris and pupil
- conjunctiva: transparent protective covering
- lacrimal apparatus: produces tears and keeps eyes
moist

Extraocular Muscles (control eye movement)

• conjugate movements: when both eyes move together, axes are parallel
• CN III (oculomotor): sup, inf, medial rectus, and inf oblique muscles
• CN IV (trochlear): sup oblique muscle
• CN VI (abducens): lateral rectus muscle

Internal Anatomy

• Outer Layer
  
  • sclera: protective white covering
  • cornea - transparent
• Middle Layer
  - choroid: highly vascularized to suppy retina
  - iris
  - pupil
• Inner Layer
  - retina: visual receptive layer

Question 2

Collecting Objective Data: Eyes

Answer 2

look at surrounding structures (symmetry, size/hair texture, evenly distributed)

Question 3

Collecting Objective Data: Eyes (eyelid inspection)

Answer 3

• inspect for fascultations/tremors
• no ptosis (drooping), lid lag, discharge, crusting
• eversion (bottom lid turns outward)/inversion(top lid turns in) of lid

Question 4

Collecting Objective Data: Eyes (inspect conjunctiva/sclera)

Answer 4

Normal - conjunctiva (Clear, moist) and sclera (white/no exudate, lesions or foreign bodies)

Abnormal

• Pterygium (abnormal growth of conjunctiva)
• Conjunctivitis (bacterial, viral, allergic infection)

Question 5

Collecting Objective Data: Eyes (inspect lens)

Answer 5

Normal - clear/transparent

Abnormal - cataracts (clouding of lens = decreased vision)

Question 6

Collecting Objective Data: Eyes (assessing iris and pupils)

Answer 6

• inspect color, shape, and size
• Direct/Consensual Light Response
  
  • direct: pupil constriction is direct response to light in eye
  • consensual: pupil constriction is response to other eye being assessed with light (indirect response)
• test for Accommodation (change in pupil dilation in response to proximity of object) (EX. pen light movement)
• test peripheral vision with Confrontation Test (have pt look directly as your nose/eyes while testing each quadrant of field of vision by having them call our number of fingers you are showing)

Question 7

Collecting Objective Data: Eyes (convergence test)

Answer 7

Convergence - motor movement of the pupil

as you move finger closer to patients face, pupil will move towards nose

Question 8

PERRLA

Answer 8

P (pupil)
E (equal)
R (round)
R (rective)
L (light)
A (accommodation)

Question 9

Visual Acuity (which CN? how to test)

Answer 9

CN II (optic)

Snellen Chart (6m or 20 ft)

• normal (6/20 or 20/20)
• abnormal (20/200) (legal blindness)
• numerator represents distance of patient from chart
• denominator represents avg distance at which the patient can read