**Core Concept**
The patient's presentation of painless loss of vision with elevated intraocular pressure (IOP) suggests a condition involving the anterior segment of the eye, specifically one that affects the drainage of aqueous humor.

**Why the Correct Answer is Right**
The patient's symptoms are most consistent with acute angle-closure glaucoma, also known as narrow-angle glaucoma. This condition occurs when the iris is pushed forward, blocking the trabecular meshwork and preventing the drainage of aqueous humor. The resulting increase in IOP can lead to optic nerve damage and vision loss. The painless nature of the vision loss is a red flag for this condition, as most patients with glaucoma present with eye pain.

**Why Each Wrong Option is Incorrect**
**Option A:** Open-angle glaucoma is a more chronic condition that typically presents with a gradual loss of peripheral vision and may not be associated with elevated IOP.
**Option B:** Uveitis is an inflammatory condition that can cause vision loss, but it is not typically associated with elevated IOP.
**Option C:** Retinal detachment is a condition that can cause sudden vision loss, but it is not typically associated with elevated IOP.

**Clinical Pearl / High-Yield Fact**
Acute angle-closure glaucoma is a medical emergency that requires prompt treatment to prevent permanent vision loss. The "red flag" symptoms for this condition include sudden vision loss, eye pain, and elevated IOP.

**Correct Answer:** C.