Hi Hakeem,
The medial portion of the eye contains the ipsilateral nasal visual field (i.e., the RIGHT nasal visual field is observed through the medial portion of the RIGHT eye). The lateral portion of the eye contains the contralateral temporal visual field (i.e., the RIGTH temporal visual field is observed through the LEFT lateral eye). This is shown in the graphic on the first few visual field deficit slides.
The right optic tract contains fibers from the lateral portion of the right eye (left temporal visual field) and the medial left eye (left nasal visual field). Therefore, a lesion to the right optic tract causes left homonymous hemianopsia.
Chrissy