Test: CN II exam

Video Link

Background/Purpose

Procedure

CN II is a special sensory nerve and can be tested in three primary ways: visual acuity, visual fields and pupillary light reflex. For visual acuity ask if the patient wears glasses. Using a Snellan chart at the recommended distance from the patient ask them to close one eye and read from left to right with the open eye. Repeat this procedure with the other eye having them read from right to left. Rate them by the smallest line they could read with 2 or less mistakes. Test the visual fields by testing peripheral vision with confrontation. Patient stares straight ahead and indicates when they see your wiggling fingers in their peripheral vision. Test in clock positions of 11/1, 1/3 and 5/7 Light is received by cranial nerve II and can be tested by having the patient place their hand between eyes. Shine the light in the right eye and observe for direct response. Shine light in the right eye again and observe left eye for consensual response. . If CN II is not working no direct or consensual response will be found with this test. Repeat for left eye
Performed: Bilaterally

Dialog

Optic nerve test

Criteria

• 20/20 vision
• bilateral, equal periphal vision at 30 degrees
• Normal constriction of pupil with light

Measurement

0.00

LOINC Code

0

Scale/Grading

Pass/Fail