A high AC/A ratio may be found in a patient with which condition?

A high AC/A ratio may be found in a patient with which condition?

• A. Exophoria
• B. Hyperopia
• C. Myopia
• D. Esophoria

Answer: (D)

AC/A ratio measures how much convergence the eyes use for each diopter of focusing. When this ratio is high, the eyes converge more than needed for the amount of accommodation, so even normal focusing can push the eyes inward. This extra convergence tends to produce an inward misalignment, or esophoria, especially when looking at near tasks. That’s why a high AC/A ratio is commonly seen in patients with esophoria. Exophoria is more often linked to a lower AC/A ratio, and hyperopia can increase accommodative demand but the diagnostic link emphasized here is the tendency toward inward deviation at near with a high AC/A ratio.

AC/A ratio measures how much convergence the eyes use for each diopter of focusing. When this ratio is high, the eyes converge more than needed for the amount of accommodation, so even normal focusing can push the eyes inward. This extra convergence tends to produce an inward misalignment, or esophoria, especially when looking at near tasks. That’s why a high AC/A ratio is commonly seen in patients with esophoria.

Exophoria is more often linked to a lower AC/A ratio, and hyperopia can increase accommodative demand but the diagnostic link emphasized here is the tendency toward inward deviation at near with a high AC/A ratio.