What is the main symptom associated with glaucoma?

The primary symptom associated with glaucoma is peripheral visual field loss. This occurs because glaucoma typically affects the optic nerve, leading to the gradual loss of vision in the outer, or peripheral, areas of the visual field. As the disease progresses, individuals may notice that they can no longer see objects to the sides while their central vision may remain intact for a longer period. This characteristic visual field loss is a hallmark of glaucoma and differentiates it from other eye conditions which may present with different symptoms.

In contrast, loss of central vision is more commonly associated with conditions like macular degeneration. Pain in the eyes is not a typical symptom of glaucoma, particularly in its most common form, open-angle glaucoma, which is often asymptomatic until advanced stages. Photophobia, or light sensitivity, can be related to various eye conditions but is not specifically tied to glaucoma as a main symptom.