SUBJECTIVE REFRACTION TECHNIQUE: DUOCHROME TEST

Course overview

THE DUOCHROME OR BICHROME TEST IS A REFRACTIVE PROCEDURE COMMONLY USED IN REFINING THE END SPHERICAL EQUIVALENT AFTER THE INITIAL OBJECTIVE REFRACTION HAS BEEN DETERMINED SUBJECTIVELY. IT IS BASED ON THE PRINCIPLE OF AXIAL OR LONGITUDINAL CHROMATIC ABERRATION, IN WHICH INCONSISTENCIES OF THE REFRACTIVE SURFACE LEAD TO THE FAILURE OF COLORS OF LIGHT TO BE EQUALLY FOCUSED AT THE SAME POINT ON A FOCUSING PLANE. THE DISPERSION PROPERTIES OF LIGHT AND THE VARIANCE IN WAVELENGTHS FACILITATE THE QUICK SEPARATION OF DIFFERENT COLORS THAT MAKE UP THE VISIBLE SPECTRUM. THIS ACTIVITY REVIEWS THE PROCEDURES AND INDICATIONS FOR THE DUO-CHROME TEST AND HOW THE INTERPROFESSIONAL TEAM CAN USE THE RESULTS TO BENEFIT PATIENT OUTCOMES.