Field of vision

Reduction and dark spots are defects in one part of the field of vision. If a large defect directly reaches the edge of the visual field, the outer edge of the defect does not have normal vision, which is called reduction. If the defect occurs within the visual field and there is still vision around it, this type of defect is called a dark spot. The reduction of the visual field can also be distinguished according to the shape of the defect: a uniform inward contraction in all directions is called a centripetal reduction; a corner defect is called a quadrant reduction; a half-sided defect is called hemianopia. Strictly speaking, the field of vision can be reduced and collapsed. Make a difference. The reduction of the field of view is only the change of the boundary. The vision in this field of view is normal, and the position of the isoline in it does not change. Reduction of the visual field is rare, it is seen in ipsilateral hemianopia or other compressive damage.