What distinguishes open-angle glaucoma from angle-closure glaucoma?

Open-angle glaucoma is characterized by a gradual development of increased intraocular pressure due to a blockade in the eyes' drainage canals, which impedes the outflow of aqueous humor. This condition often progresses slowly and without noticeable symptoms in the early stages, which can lead to significant damage to the optic nerve before it is detected. The gradual nature of this type of glaucoma differentiates it from angle-closure glaucoma, which occurs suddenly due to a blockage of the drainage angle in the eye, resulting in a rapid increase in intraocular pressure and often accompanied by acute symptoms like severe eye pain, blurred vision, and nausea.

The option regarding sudden occurrence and reversibility does not apply to open-angle glaucoma, as it develops over time and is not reversible once damage occurs. Furthermore, while glaucoma can affect individuals of various ages, it primarily develops in adults rather than children. Lastly, open-angle glaucoma may not present obvious symptoms initially, but it does not mean the condition has "no symptoms at all," as it can lead to vision loss if untreated, indicating that some awareness of the condition is essential for prompt management.