- Remember that it is important to check a patient's peripheral vision when concerned about stroke, and when performing a neurological exam in general.
- Recognizing grossly abnormal peripheral vision often suggests the presence of various types of visual field cuts and helps localize a stroke lesion.
- When performing a general, very gross examination for peripheral vision abnormalities:
- It is sometimes helpful to ask the patient to cover the eye that you are NOT checking for abnormality at the time.
- Ask the patient to look straight ahead.
- Ask the patient to tell you when they are able to see the long, narrow object (i.e. your finger, a pencil, etc.) that you slowly move forward into their view, starting from the point where the finger tips of the patient's laterally abducted arm would be (i.e. the object begins at a distance approximately equal to the patient's arm length).
- Using this axis of reference, normal peripheral vision should occur at 45 degrees or less.