10 Different Types of Glaucoma And How To Identify Each One

3. Normal-Tension Glaucoma (NTG)

NTG is also known as low-tension or normal pressure glaucoma because the pressure in the eye is not increased significantly. The main cause is the optic nerve becoming damaged, but the mystery lies in how it becomes damaged without the pressure. The cause remains unknown, but those at higher risk appear to have a family history of it, be of Japanese heritage, or are affected by systemic heart disease. It is diagnosed by examination of the optic nerve.