Physiological diplopia is characterized by

Physiological diplopia is characterized by

• A. Non fixated objects fall on non corresponding points and appear to be diplopia
• B. Diplopia only occurs with direct gaze
• C. It is a pathological condition unrelated to normal vision
• D. It occurs only in monocular viewing

Answer: (A)

When both eyes are used, the visual system tries to fuse images from corresponding retinal points. There’s a region around the horopter, known as Panum’s fusional area, where small disparities can still be fused into a single image. Physiological diplopia happens when non-fixated objects project onto non-corresponding retinal points and lie outside that fusion area. In other words, the two eyes’ images for those objects can no longer be merged into one, so you perceive two distinct images. This is a normal, binocular phenomenon that occurs with typical viewing, not a disease. So the statement that non-fixated objects fall on non-corresponding points and appear diplopic captures the essence: diplopia arises from disparity that exceeds the brain’s fusion capacity. The other ideas don’t fit: diplopia isn’t limited to direct gaze, isn’t inherently pathological, and isn’t restricted to monocular viewing.

When both eyes are used, the visual system tries to fuse images from corresponding retinal points. There’s a region around the horopter, known as Panum’s fusional area, where small disparities can still be fused into a single image. Physiological diplopia happens when non-fixated objects project onto non-corresponding retinal points and lie outside that fusion area. In other words, the two eyes’ images for those objects can no longer be merged into one, so you perceive two distinct images. This is a normal, binocular phenomenon that occurs with typical viewing, not a disease.

So the statement that non-fixated objects fall on non-corresponding points and appear diplopic captures the essence: diplopia arises from disparity that exceeds the brain’s fusion capacity. The other ideas don’t fit: diplopia isn’t limited to direct gaze, isn’t inherently pathological, and isn’t restricted to monocular viewing.