Diagnosing glaucoma is difficult because it takes several years for damage to be noticed even to the highly trained. However, there are exceptions depending on the type of glaucoma. Primary Open Angle Glaucoma , is the most common type. It is usually very slow in onset and progression. Traumatic Glaucoma occurs when and injury to the eye makes the optic nerve more susceptible to small changes in IOP, and alters the structure of the drainage system.
Traumatic glaucoma can show up many years after a significant injury.
Acute Angle Closure Glaucoma is relatively rare. It can be due to iris dilation and blocking the drainage canals. This leads to a rapid increase in pressure, and sudden vision loss if not treated quickly. It occurs most commonly in the elderly. Sometimes people have high eye pressure without glaucoma.