Which patient will fail BAF and MAF testing?

• A. Fusional Vergence Dysfunction
• B. Convergence Insufficiency
• C. Accommodative Infacility
• D. Convergence Excess

Answer: (C)

Accommodative facility is the ability to quickly and accurately change focus between distances, and tests like the Monocular Accommodative Facility (MAF) and Binocular Accommodative Facility (BAF) measure how fast the eyes can shift accommodation while either occluded or open to both eyes. In accommodative infacility, the system that adjusts focus is slow or hesitant, so the patient struggles to flip between plus and minus lenses promptly. This slowness shows up in both monocular and binocular testing, causing failures on MAF and BAF because the accommodations can’t be modulated quickly enough regardless of whether the eyes are aligned or not. Other conditions—fusional vergence dysfunction, convergence insufficiency, and convergence excess—primarily affect vergence or near point tasks rather than the speed of changing accommodation, so they don’t inherently cause failures on both accommodative facility tests. Therefore, the patient with Accommodative Infacility best explains why both MAF and BAF testing would fail.