4.5 - Binasal Field Loss: A Rare but Disruptive Pattern

Your vision seems okay—until you keep missing steps, bumping into corners, or feeling strangely closed in. It might not be anxiety—it could be binasal field loss.

Imagine reading through binoculars—but instead of a clear, wide image, something blocks the inner halves of each eye. You’re left seeing the outer world, but your center is fragmented. That’s binasal field loss, and while it’s rare, it can feel incredibly disorienting.

In this final post of the Vision & the Visual Field Series, we’ll unpack this uncommon visual field pattern, its causes, how it affects perception, and how vision rehabilitation can help restore confidence and control.

What Is Binasal Field Loss?

Binasal hemianopia is the loss of vision in the nasal (inner) parts of each eye’s visual field—closest to the nose. While less common than other types, it may indicate serious underlying conditions involving:

• Bilateral optic nerve compression

• Glaucoma (advanced)

• Hydrocephalus

• Raised intracranial pressure

• Congenital anomalies or optic nerve coloboma

Sometimes, it appears as a result of trauma, or in rare cases, without a clearly defined cause (idiopathic).

Everyday Impacts

• Misjudging doorframes or objects near the centerline

• Difficulty crossing streets or focusing on central tasks

• Reduced depth perception

• Increased falls or missteps

• Visual discomfort in cluttered environments

• Feelings of isolation or confusion

📊 Although binasal field loss accounts for less than 1% of all visual field cases, its symptoms can mimic emotional distress or balance disorders, leading to misdiagnosis.

Vision Rehabilitation Strategies

• Comprehensive field testing to define and monitor the exact loss

• Contrast and lighting modifications to improve object awareness

• Environmental adaptation (e.g. widened visual spacing, decluttering)

• Mobility support and scanning strategies to improve spatial perception

• Referral for neurological or optic nerve evaluation

In some cases, prism lenses may be trialed—but results vary based on severity and origin.

Quote to Remember

Final Thoughts

Binasal field loss may be rare, but its impact can be deeply felt—physically and emotionally. With thorough evaluation and support from a skilled vision rehabilitation team, even the most unusual field patterns can become manageable.