If two eyes share the same objective strabismic angle, which type tends to experience more diplopia: UHAC or NRC?

• A. UHAC
• B. NRC
• C. PAC 1
• D. PAC 2

Answer: (B)

Diplopia in strabismus depends on how the brain maps the two eyes’ images to retinal points. If the two eyes misalign by the same objective angle, the likelihood of double vision hinges on whether retinal correspondence is normal or anomalous.

With normal retinal correspondence, the brain uses corresponding retinal points to fuse images. When the eyes are misaligned by the same angle, those images don’t align on corresponding points as effectively, so fusion fails and diplopia occurs more readily.

If there is an anomalous retinal correspondence, the brain has adapted by remapping where images from the two eyes correspond, allowing fusion to occur despite the misalignment, which reduces diplopia.

Therefore, the type with normal retinal correspondence tends to experience more diplopia, making NRC the more diplopia-prone option in this scenario.