Which of the following is NOT a cause of acute, painless visual loss?

Acute glaucoma is indeed associated with a painful increase in intraocular pressure, which typically leads to acute visual loss accompanied by significant discomfort or pain. The other conditions listed, such as retinal detachment, vitreous hemorrhage, and central retinal artery occlusion, can cause acute visual loss without pain.

Retinal detachment often presents with symptoms such as flashes of light, floaters, or a curtain-like shadow over the vision, but lacks physical pain. Similarly, vitreous hemorrhage can cause sudden vision loss or blurring, often without accompanying pain, typically due to bleeding in the vitreous cavity. Central retinal artery occlusion can lead to sudden, painless vision loss due to an interruption of blood supply to the retina, often described as a "stroke of the eye."

Understanding the differentiation in symptoms, particularly the presence or absence of pain, is crucial for accurate diagnosis and management of sudden visual changes.