**Core Concept**
Cloudy cornea refers to a condition where the cornea, the transparent outer layer of the eye, becomes opaque or hazy due to various underlying causes. This can be caused by inflammation, injury, or degenerative changes in the cornea.

**Why the Correct Answer is Right**
Cloudy cornea is typically associated with conditions that affect the corneal stroma, such as keratoconus, corneal edema, or corneal dystrophy. In keratoconus, the cornea thins and bulges, leading to a conical shape and cloudiness. Corneal edema, on the other hand, occurs when fluid accumulates in the corneal stroma, causing it to swell and become opaque. Corneal dystrophies, such as Fuchs' endothelial dystrophy, are genetic conditions that affect the corneal endothelium, leading to cloudiness and vision loss.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because cloudy cornea is not typically associated with conjunctivitis, which is an inflammation of the conjunctiva, the thin membrane covering the white part of the eye and the inside of the eyelids.
* **Option B:** This option is incorrect because posterior uveitis refers to inflammation of the posterior segment of the eye, including the retina and choroid, and is not directly associated with cloudy cornea.
* **Option C:** This option is incorrect because cataract refers to a clouding of the lens inside the eye, rather than the cornea.

**Clinical Pearl / High-Yield Fact**
It's essential to differentiate between cloudy cornea and cataract, as the treatment and management of these conditions differ significantly.

**Correct Answer:** C. Keratoconus