What are the Morgan's norms for Near BO smooth vergences?

What are the Morgan's norms for Near BO smooth vergences?

• A. -----/7/4
• B. 9/19/10
• C. 13/21/13
• D. 17/21/11

Answer: (D)

Morgan's norms give reference values for how much convergence (near BO, base-out) the eyes can produce under normal, smooth viewing at near distances. For near BO smooth vergences, the standard normative triplet is about 17/21/11 in prism diopters. That is why the option with 17/21/11 is the correct one—it reflects the typical near convergence range used as a benchmark in clinical binocular vision assessment. If a patient’s near BO smooth vergences are close to these values, their convergence reserves are within normal limits. Significantly lower values can indicate a convergence insufficiency or related binocular issue, while higher values are less common but would indicate stronger fusional reserves.

Morgan's norms give reference values for how much convergence (near BO, base-out) the eyes can produce under normal, smooth viewing at near distances. For near BO smooth vergences, the standard normative triplet is about 17/21/11 in prism diopters. That is why the option with 17/21/11 is the correct one—it reflects the typical near convergence range used as a benchmark in clinical binocular vision assessment. If a patient’s near BO smooth vergences are close to these values, their convergence reserves are within normal limits. Significantly lower values can indicate a convergence insufficiency or related binocular issue, while higher values are less common but would indicate stronger fusional reserves.