Blindness can be caused by injuries to the eye or the other structures involved in the visual pathway. For example, the cuts in the optic tract, the lateral geniculate nucleus (LGN) or striate cortex (region VI) of the cortex result in hemianopia, which refers to blindness of one entire side of visual field.
Scotoma is a visual field defect in which the field of vision is partially altered. Small lesions in region VI causes scotoma.
Thus, the blank can be filled scotomas.