Previously known ocular and systemic risk factors for normal tension glaucoma (NTG) include myopia, peripapillary atrophy, disc haemorrhage, migraine, obstructive sleep apnoea, thyroid disease and cerebral infarction. However, most NTG risk factor studies have examined patients aged 40 years and older. The aim of this retrospective, population based, case control study was to assess risk factors for NTG in a young population. Among participants from the Korea National Health and Nutrition Examination Survey 2009-2010, 80 subjects with NTG aged 19-39 years and 4015 controls were included in the study. Variables assessed included diabetes mellitus, hypertension, cholesterol levels, migraine, family history of glaucoma, BMI, cold extremity, fasting plasma glucose, haemoglobin level and refractive error. Results showed that fasting capillary glucose ≥200mmol/L, high myopia (SE≺-6D) and low HDL cholesterol were associated with NTG in a young Korean population.