Shape or form is defined as areas of visual field that are set off from the rest of the field by ________________.
Answers
Answer:
an absolute scotoma
Explanation:
The field of vision is that portion of space in which objects are visible at the same moment during steady fixation of gaze in one direction. The monocular visual field consists of central vision, which includes the inner 30 degrees of vision and central fixation, and the peripheral visual field, which extends 100 degrees laterally, 60 degrees medially, 60 degrees upward, and 75 degrees downward (Figure 116.1) A vertical line bisects central fixation and divides the visual field into a nasal and temporal hemifield. Situated in the temporal hemifield is the normal blind spot approximately 12 to 17 degrees from fixation and 1.5 degrees below the horizontal meridian. The blindspot is represented on a visual field chart by an absolute scotoma and corresponds anatomically to the scleral canal through which the retinal nerve fibers leave the eye at the optic disk.
Figure 116.1. Normal visual field.
Figure 116.1
Normal visual field. I-4e is a larger target than I-2e.
A normal visual field is an island of vision measuring 90 degrees temporally to central Fixation, 50 degrees superiorly and nasally, and 60 degrees inferiorly. Visual acuity increases from movement discrimination in the extreme peripheral vision to better than 20/20 in the center of vision. Depression or absence of vision anywhere in the island of vision is abnormal.
Answer:
primitive
Explanation: