Dipping lenses in front of habitual correction is not an adequate way to check refraction. True or False?

• A. True
• B. False
• C. Cannot be determined
• D. Sometimes

Answer: (A)

The key idea is that an accurate refraction requires a controlled testing process, not a quick check using lenses over the patient’s current glasses. Placing additional lenses in front of habitual correction doesn’t reveal the true refractive error because the patient’s accommodation and the existing prescription still influence the outcome. This method also changes the effective power due to vertex distance differences and won’t reliably identify astigmatism, axis, or any residual errors. To truly assess refraction, you need objective and subjective testing with proper equipment (phoropter or trial lenses) at the correct working distance, and adjustments are made to obtain the best corrected vision. Therefore, this approach is not adequate for checking refraction.