Junctional scotoma

Inferonasal fibres of the optic nerve which go into the contralateral optic nerve 4 mm before crossing over to the opposite optic tract. A lesion here produces a junctional scotoma.

Compression of the optic nerve near the chiasm may produce a superior temporal quadrant defect in the contralateral eye (junctional scotoma “pie in the sky” defect) from injury to the anterior Wilbrand's knee.