What is a common finding in open-angle glaucoma?

Open-angle glaucoma is characterized by a gradual, progressive loss of peripheral vision, which can eventually lead to tunnel vision if left untreated. This condition results from increased intraocular pressure that damages the optic nerve over time. Patients often do not notice vision changes until significant damage has occurred. Thus, peripheral vision loss is a hallmark sign of this type of glaucoma.

The other choices represent visual disturbances not typically associated with open-angle glaucoma. Night blindness is more commonly linked to conditions affecting the retina, such as retinitis pigmentosa, rather than glaucoma. Color vision deficiency is often related to genetic factors or conditions that affect the retina or optic nerve but is not a direct result of open-angle glaucoma. Flashes of light are indicative of retinal detachment or vitreous detachment rather than glaucoma itself, which does not typically present with such visual phenomena.