Assessing Visual Acuity with a Snellen Chart

Introduction

• Purpose: To assess visual acuity using a Snellen chart.
• Involves testing cranial nerve 2 (optic nerve).

Equipment Needed

• Snellen chart

Procedure

1. Setup

   • Have the patient stand about 20 feet from the Snellen chart.
   • Ask the patient if they wear glasses. If yes, they should wear them during the test.

2. Testing Steps

   • Right Eye: Cover the left eye and read the lowest line possible.
   • Left Eye: Cover the right eye and read the lowest line possible.
   • Both Eyes: Read the lowest line possible with both eyes open.

3. Reading the Results

   • Example given: If the patient reads line 8, they have 20/20 vision.
   • Interpretation:
     • 20/20 Vision: Able to see the same line at 20 feet as a person with normal vision.
     • Less than 20/20 (e.g., 20/30): The patient sees at 20 feet what someone with normal vision sees at 30 feet.

Conclusion

• Visual acuity assessment using a Snellen chart provides a quick measure of vision quality.
• Results help to determine if a patient has normal vision or any deficits.

Additional Note

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