During NRV/PRV testing, which sequence accurately describes changes before and after blur and the overall vergence measurement?

During NRV/PRV testing, which sequence accurately describes changes before and after blur and the overall vergence measurement?

• A. Before blur: NFRV; After blur: NAV; Total: TNV
• B. Before blur: NAV; After blur: NFRV; Total: TNV
• C. Before blur: PFRV; After blur: PAV; Total: TPV
• D. Before blur: NFRV; After blur: PAV; Total: TPV

Answer: (A)

This question tests how vergence is parsed when accommodation is altered during NRV/PRV testing. In this approach you first measure a baseline vergence that reflects non-accommodative (or non-relaxed) driving forces—the state before blur. Then you blur the target to relax accommodation, which reveals the accommodative vergence component that kicks in with blurred vision. The overall vergence you report is the combination (sum) of these two contributions. The sequence that starts with the non-accommodative vergence before blur and then shows the accommodative vergence after blur, yielding the total vergence, matches how NRV/PRV testing is interpreted.

This question tests how vergence is parsed when accommodation is altered during NRV/PRV testing. In this approach you first measure a baseline vergence that reflects non-accommodative (or non-relaxed) driving forces—the state before blur. Then you blur the target to relax accommodation, which reveals the accommodative vergence component that kicks in with blurred vision. The overall vergence you report is the combination (sum) of these two contributions. The sequence that starts with the non-accommodative vergence before blur and then shows the accommodative vergence after blur, yielding the total vergence, matches how NRV/PRV testing is interpreted.