**Core Concept**
Painless sudden visual loss is a characteristic feature of various ocular and neurologic conditions. This symptom is often associated with vascular, inflammatory, or traumatic causes that affect the retina or optic nerve.

**Why the Correct Answer is Right**
Sudden painless visual loss can occur due to conditions like central retinal artery occlusion, central serous chorioretinopathy, or optic neuritis. These conditions typically involve damage to the retina or optic nerve, leading to a sudden loss of vision without accompanying pain. The underlying mechanisms include retinal ischemia, choroidal effusion, or inflammation of the optic nerve.

**Why Each Wrong Option is Incorrect**
**Option A:** Not a typical cause of painless sudden visual loss. Typically associated with severe eye pain.
**Option B:** Not typically associated with painless sudden visual loss. Often presents with severe eye pain and proptosis.
**Option C:** Actually a possible cause of painless sudden visual loss, such as central retinal artery occlusion or central serous chorioretinopathy.

**Clinical Pearl / High-Yield Fact**
In cases of sudden painless visual loss, it's essential to perform a thorough ophthalmic examination, including fundoscopy and visual field testing, to determine the underlying cause.

**Correct Answer: B. Optic neuritis is not typically associated with painless sudden visual loss.**