a small island of blindness in the central visual field surrounding, but not including, the fovea centralis. Monocular paracentral scotoma (affecting one eye) results from impairment of the peripheral visual system, such as from glaucoma or optic nerve atrophy; homonymous paracentral scotoma (affecting both eyes) arises from injury to the central visual system posterior to the lateral geniculate nucleus. Patients with homonymous paracentral scotoma typically have difficulties with reading (hemianopic dyslexia). See also scotoma.