Dilated pupils three to four months after optic nerve injury are usually caused by loss of vision due to severe optic nerve injury, or by stimulation of the sympathetic nerves that regulate pupil size, or by damage to the vagus nerve.
If the optic nerve damage is severe, and the condition eventually progresses to blindness, it can lead to the loss of light reflex in the injured eye, resulting in pupil dilation.
If the patient’s injured eye is combined with orbital damage, resulting in stimulation of sympathetic nerve fibers or vagus nerve fibers are damaged, so that the pupil dilation and reduction of the power imbalance, the patient may appear pupil dilation.
It is recommended that patients with pupil abnormalities seek prompt medical attention to evaluate their condition and follow the doctor’s instructions for treatment.