Abstract Purpose A high incidence of clinical optic disc edema has been observed at high altitudes; however, most patients experience complete regression upon returning to lowlands and do not report visual symptoms such as vision loss or visual field defects. Here, we report six patients with optic disc edema and significantly decreased visual function after high-altitude exposure. Methods Clinical characteristics, intracranial pressure, 24-hour ambulatory blood pressure, and polysomnography data were retrospectively collected from patients presenting with optic disc edema and decreased visual function after high-altitude exposure on the Tibetan plateau between October 2020 and September 2023 at the neuro-ophthalmology department of the People’s Liberation Army General Hospital in China. Results Eleven eyes of six patients (five males and one female) were included, with a mean age of 47.3 ± 11.76 years (range 28–63). Simultaneous bilateral eye involvement was present in five of the six patients. All cases presented with diffuse disc edema at onset, which gradually resolved within 8 weeks. There was a definite time lag, ranging from 7 days to 1 month, between arrival at high altitude and symptom onset. All patients had normal intracranial pressure. Mean visual acuity was worst (20/50) at 2 weeks, and the best mean visual acuity was 20/30 at 6 months. Visual field defects were observed in all patients at the early stage of the disease, with some residual defects remaining. One patient had a small cup-to-disc ratio in the contralateral eye, while the other five could not be assessed due to bilateral optic disc edema. One patient had hypertension and severe sleep apnea; one had hypercholesterolemia and hypertension; and one had hypercholesterolemia alone. Conclusion Optic disc edema with decreased visual function and visual field defects can occur after high-altitude exposure.