What is a typical characteristic of the vision changes associated with primary open-angle glaucoma?

In primary open-angle glaucoma, a hallmark characteristic is the gradual loss of peripheral vision, often referred to as "tunnel vision." This condition progresses slowly and often goes unnoticed until a significant amount of vision is lost. The degeneration of the optic nerve, typically associated with increased intraocular pressure, leads to this peripheral vision loss while the central vision remains largely intact until the later stages of the disease.

Understanding this characteristic is crucial for early detection and management of the condition, as patients may not experience any obvious symptoms until considerable damage has occurred. This contrasts with other eye conditions that may show sudden vision loss or different types of visual disturbances, making the gradual nature of peripheral vision loss in open-angle glaucoma particularly significant for diagnosis and treatment.