BACKGROUND: As the prevalence of obesity increases, so, too, do the prevalences of weight-related diseases and surgical procedures to promote weight loss. It is important for neuro-ophthalmologists to be familiar with these procedures and possible downstream effects on afferent and efferent visual function. EVIDENCE ACQUISITION: Review of ophthalmology, neurology, general surgery, obesity, endocrinology, nutrition, psychiatry, and neurosurgery literature. RESULTS: Bariatric surgery is a safe and effective treatment for weight loss in obese individuals. There is Level IV evidence that it is associated with improvement in idiopathic intracranial hypertension (IIH). Laboratory nutrient deficiencies are common following some types of bariatric procedures. Symptomatic deficiencies are less common but can be devastating. Thiamine deficiency can cause nystagmus and other symptoms in weeks to months after surgery, whereas B12 or copper deficiency can cause optic neuropathy in years to decades following bariatric surgery. CONCLUSIONS: Bariatric surgery is a potential treatment for IIH. Postoperative vitamin deficiencies may cause nystagmus, optic neuropathy, nyctalopia, and/or ophthalmoparesis weeks to years after surgery.