If the patient reports that the GREEN SIDE is CLEARER during the binocular duochrome test, what should you add to both eyes?

In the binocular duochrome test, the patient compares the clarity of letters or symbols on red and green backgrounds. If the patient reports that the green side appears clearer, it indicates a tendency towards under-correction of their refractive error. This is because the green background, which is associated with longer wavelengths of light, tends to be focused more easily and often means that more plus power may be needed in the prescription.

Adding plus power helps to enhance clarity by effectively bringing light rays more in line with the patient's visual system, addressing any hyperopia that may be contributing to the perceived difference in clarity. This adjustment not only helps correct the refractive error but also balances the vision between both eyes if there is a disparity. Thus, adding plus power is a logical and effective way to improve overall visual clarity for the patient.