During FCC, if the patient reports that the horizontal lines are darker, which lens power should be added?

During FCC, if the patient reports that the horizontal lines are darker, which lens power should be added?

• A. Add Minus
• B. Add Plus
• C. No Change
• D. Subtract Both

Answer: (B)

During FCC, you’re using a cross-cylinder style approach to fine-tune the two principal meridians by listening to which orientation of lines the patient perceives as darker or sharper. If the horizontal lines become darker when you introduce positive (plus) power, that tells you the horizontal meridian is under-focused and needs more positive power to move its focal line forward onto the retina. Adding plus in that meridian sharpens the horizontal lines and improves their contrast, which is why that is the best adjustment. Subtracting power would pull the focus in the opposite direction and typically worsen the horizontal lines’ clarity, and no change wouldn’t address the discrepancy the patient is reporting.

During FCC, you’re using a cross-cylinder style approach to fine-tune the two principal meridians by listening to which orientation of lines the patient perceives as darker or sharper. If the horizontal lines become darker when you introduce positive (plus) power, that tells you the horizontal meridian is under-focused and needs more positive power to move its focal line forward onto the retina. Adding plus in that meridian sharpens the horizontal lines and improves their contrast, which is why that is the best adjustment. Subtracting power would pull the focus in the opposite direction and typically worsen the horizontal lines’ clarity, and no change wouldn’t address the discrepancy the patient is reporting.