Abstract: Many perplexities and difficulties in the clinical and research of normal tension glaucoma (NTG) arise not only from the disease itself, but also from the limitations of our clinical thinking and understanding methods. The relationship between the clinical manifestations and its pathological nature is complicated and far apart in NTG. So various studies based on clinical thinking are difficult to really solve the pathogenesis problems. The basic problems and particularity of NTG are pointed out as "normal intraocular pressure(IOP)" and its relationship with optic nerve damage. The range of IOP in normal population is not equal to IOP in normal individual. IOP  values are not qualitative differences, only quantitative differneces. In NTG, even if the IOP is normal, it has a "physiological" compression effect on the eye tissue. Therefore, it is necessory to comprehensively and reasonably explain the relationship between the IOP and the optic nerve damage from the etiology, phathophysiology, pathology, to clinical manifestations in NTG. (Ophthalmol CHN, 2020, 29: 6-8)

Key words: normal tension glaucoma, pathophysiology