Nerve05/disorders of the spinal cord and optic pathway/basics of optic pathway
１．When an image goes through the lens (of an eye, just as with the lens in the camera), the image is projected to the other side of the center of the lens. So, the images on the outer side of the visual field for either eye (the spade and diamond ), is projected to the inner half of the retina, and the image on the inner side of the visual field for either eye (the heart and club) is projected to the outer half of the retina.
２．Half of the fibers in the optic nerve cross the right-left midline at the optic chiasma as shown in the figure. The fibers from the inner half of the retina cross to the other side. The fibers from the outer half of the retina do not cross the midline and reach the cerebral cortex on the same side.
Above is both the basic information and the summary. Let's separate the visual fields into 4 in the following 4 steps.
Challenge Quiz
Because of the lens, the image in the outer side of the center of an eye, is projected to the outer inner half of the retina.
Because of the lens, the image in the inner side of the center of an eye, is projected to the outer inner half of the retina.
Most fibers in the right optic nerve cross to the left at the optic chiasma. true false
Most fibers in the left optic nerve cross to the right at the optic chiasma. true false
In the optic nerve, fibers from the inner half of the retina do do not cross the right-left midline.
In the optic nerve, fibers from the outer half of the retina do do not cross the right-left midline.