Required Materials
- Penlight.
Procedure
- Ensure the room is dimly lit, but that there is sufficient light to observe the transition between pupil and iris.
- Position yourself opposite the patient.
- Place your hand, like a screen, between both eyes on the nasal bridge of the patient.
- Use the ulnar side of the hand to rest on the nasal bridge. Make sure that light cannot leak through to the other eye [Figure 37].
Figure 37
- Illuminate the right eye from an angle of approximately 45°. Be careful not to shine the light straight into the eye; it will temporarily blind the patient.
- Check if this light stimulation narrows the pupil and whether it widens again once the stimulus is gone (direct pupillary reaction to light).
- Briefly illuminate the right eye once more and observe if the pupil of the left eye narrows and whether it widens again when the stimulus is removed (indirect pupillary reaction to light).
- Repeat this illumination procedure for the left eye.