The optic tract is a vital part of the visual pathway carrying information from the retina to the brain’s lateral geniculate nucleus. A lesion in the optic tract results in characteristic visual deficits corresponding to the affected fibers.

Visual Field Impairment From Left Optic Tract Lesion

• The optic tract contains fibers from both eyes corresponding to the contralateral visual field.

• A lesion in the left optic tract causes loss of vision in the right half of the visual field in both eyes, a condition known as right homonymous hemianopia.

• This happens because nasal retinal fibers from the right eye and temporal retinal fibers from the left eye, representing the right visual field, travel through the left optic tract.

Explanation of the Options

• (1) Blindness in the left eye but right eye’s visual field intact: Incorrect, as optic tract lesions cause homonymous field loss, not monocular blindness.

• (2) Blindness in the right half of the visual fields of both eyes: Incorrect in this case; this describes a lesion in the right optic tract. For the left optic tract lesion, blindness will be in the right half; the option wording suggests otherwise but is ambiguous.

• (3) Blindness in left half of left eye and right half of right eye: Incorrect; this pattern would mean hemianopia split between eyes (heteronymous), which occurs at the chiasm, not optic tract.

• (4) Blindness in left half of visual field of both eyes: Incorrect; a lesion in the left optic tract causes contralateral (right) homonymous field loss.

The correct description of symptoms in a left optic tract lesion is homonymous hemianopia of the right visual field, which corresponds with loss in right half of visual field of both eyes.

Since the options are confusing in wording and none strictly describes right homonymous hemianopia, the closest and correct standardized answer understanding is:

(2) Blindness in the right half of the visual fields of both eyes