Yeasn YPA-2100, Руководство пользователя, Страница: 59 / 91

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according to right eye heperphpria until it turns into a
cross.
Exo left
eye hyperphoria
Correct the horizontal heterophoria according to
exophoria method and correct the vertical heterophoria
according to right eye heperphpria until it turns into a
cross.
Note: When adding prismatic power, only add one eye’s prismatic power instead of two eyes’ prismatic powers.
5.5.4 Cross ring test (heterophoria)
Test purpose: to test heterophoria
Test sighting mark: cross ring sighting mark
Assistant lens: Binocular rotatory prime
Right eye red optical filter, left eye green optical filter (red and green cross ring sighting mark)
Binocular circular polarized optical filter (polarized cross ring sighting mark)
1. Call in cross ring sighting mark.
2. Ask the patient about the sighting mark he sees and test according his answers.
Sighting
mark shape
Diagnosis Correction
No heterophoria Align eye position, no need for correction.
Esophoria
Increase BO prismatic power until it the cross goes in
the center of the circle.
Exophoria
Increase BI prismatic power until it the cross goes in
the center of the circle.
Left eye
hyperphoria
Increase BU prismatic power in right eye and BD
prismatic power in left eye until it the cross goes in the
center of the circle.
Right eye
hyperphoria
Increase BU prismatic power in left eye and BD
prismatic power in right eye until it the cross goes in
the center of the circle.