A nurse is assessing a client’s cranial nerves. Which of the following methods should the nurse use to assess cranial nerve II?
A.
Listen to the client’s speech
B.
Ask the client to identify scented aromas
C.
Ask the client to clench his teeth
D.
Ask the client to read a Snellen chart
The Correct Answer and Explanation is:
The correct answer is D. Ask the client to read a Snellen chart.
Explanation:
Cranial nerve II, also known as the optic nerve, is primarily responsible for vision. To assess the function of this nerve, a nurse evaluates the client’s visual acuity, which is the clarity or sharpness of vision. One of the standard methods for assessing visual acuity is by using a Snellen chart. The Snellen chart is a tool that displays letters in varying sizes and is used to measure how well a person can see at a distance. This test helps determine if the optic nerve is functioning properly and if the client has normal visual acuity or if there are any deficiencies that may indicate issues with the nerve.
Here’s how the Snellen chart test is performed:
- Preparation: The client is positioned 20 feet away from the Snellen chart, which is placed at eye level. If testing is conducted in a smaller space, a card with the same letters can be used at a closer distance with appropriate adjustments made for distance.
- Testing: The client is asked to cover one eye and read the smallest line of letters they can see clearly. This is done first for one eye and then for the other eye. The results are recorded as a fraction, such as 20/20, where 20/20 is considered normal visual acuity. If the client cannot read the smallest letters on the chart, the test is repeated with the letters enlarged.
- Evaluation: The results are compared to normal values and can help identify if there is any impairment or visual defect that may be related to the optic nerve.
Why the other options are incorrect:
- A. Listen to the client’s speech: This tests cranial nerve IX (glossopharyngeal) and X (vagus), which are involved in speech and swallowing.
- B. Ask the client to identify scented aromas: This tests cranial nerve I (olfactory), which is responsible for the sense of smell.
- C. Ask the client to clench his teeth: This tests cranial nerve V (trigeminal), which is involved in mastication (chewing) and facial sensation.
Assessing cranial nerve II with the Snellen chart is essential for evaluating visual acuity and diagnosing potential issues with the optic nerve.