Visual field defects

Amaurosis

unilateral optic nerve lesion which produces blindness in the affected eye

Bitemporal hemianopia

Lesions of optic chiasm interrupts fibers from nasal portion of retina which represents the temporal eye field

Contralateral homonymous hemianopia

lesion in the optic tract causes vision loss in the opposite half of the visual field for both eyes. For example, a right optic tract lesion leads to loss of the left visual field in both eyes.

Homonymous hemianopia

condition where there is a loss of vision in the same side of the visual field in both eyes. It occurs due to damage to the visual pathway beyond the optic chiasm, such as in the optic tract, leading to loss of either the right or left visual field.

Contralateral Upper Quadrantanopia:

This occurs when there is a lesion in the Meyer's loop portion of the optic radiation, which passes through the temporal lobe. It causes vision loss in the upper quadrant of the visual field on the opposite side of the lesion for both eyes.

Contralateral Lower Quadrantanopia:

This happens due to a lesion in the medial part of the optic radiation located in the parietal lobe. It results in loss of vision in the lower quadrant of the visual field on the opposite side of the lesion for both eyes.

unilateral optic nerve lesion

the affected eye loses both the direct and consensual light response due to disruption of the afferent limb, but the unaffected eye still shows both responses. In contrast, a lesion of the efferent limb (oculomotor or ciliary ganglion) results in no direct or consensual light response in the affected eye, while the optic radiation or visual cortex lesion does not impair the pupillary reflex.