A patient with chronic alcoholism recently complained of a gradual loss of vision. After detailed examination, other causes were ruled out, and nutritional amblyopia due to long-term alcohol consumption was considered, probably due to optic neuropathy caused by a deficiency of one or several B vitamins. The initial symptom of this patient is difficulty in reading small words and color discrimination, which gradually progresses over days to weeks to decreased visual sensitivity in both eyes and blurred vision, but not to total blindness, without other signs in the eye. In the late stage, mild optic nerve atrophy can be seen, which may be accompanied by other polyneuropathies due to nutritional and metabolic disorders. For such patients, alcohol should be abstained or reduced as much as possible, and adequate amounts of B vitamins should be supplemented.