What visual field defect results from a lesion in the left optic tract?

A lesion in the left optic tract leads to a right-sided homonymous hemianopia. This is because the optic tract carries visual information from the opposite (right) visual field of both eyes. So, if the left optic tract is damaged, it results in a loss of vision in the right half of the visual field, which is termed right homonymous hemianopia.

In this case, the term "incongruous" refers to the degree of similarity between the visual field defects in both eyes. When referring to hemianopia, "incongruity" often indicates that each eye's defects do not align perfectly, but in the case of a lesion affecting an entire optic tract, the affects tend to be congruous, rather than incongruous.

Thus, the correct answer emphasizes that the visual field loss would be in the right visual field due to the lesions affecting how signals are processed from the left optic tract to the visual cortex.