20
SECONDARY TEST SLIDE (1000-21)
VERTICAL PHORIA
1. Test #4
2. Right Eye Illuminated
3. Left Eye Occluded
Left Eye Right Eye
Ask the subject, "Do you see a series of musical notes?" If the subject
says, “yes”, ask, "How many?" The answer is 7. Tell the subject a red
broken line will appear. Simultaneously turn LEFT switch ON.
Ask the subject, "The line crosses the round part of which note?"
The red broken line passing through note #4 is ideal or orthophoric.
Anywhere from 2 ½ to 5 ½ is the accepted norm.
The Vertical Phoria Test measures how the eyes work together on the
vertical plane.
• Each number represents ½ prism diopter of power.
NOTE: This test cannot be given to a subject with vision in only one eye;
this is a binocular test only.
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