**Core Concept**
Keratic precipitates are deposits of inflammatory cells that accumulate on the corneal endothelium, which is the innermost layer of the cornea. This phenomenon is often associated with anterior uveitis, a condition characterized by inflammation of the anterior segment of the eye.

**Why the Correct Answer is Right**
Keratic precipitates form due to the migration of inflammatory cells, primarily lymphocytes and macrophages, from the anterior chamber into the corneal stroma. These cells are attracted to the corneal endothelium, which is rich in antigen-presenting cells, and deposit their debris, resulting in the formation of keratic precipitates. The corneal endothelium plays a crucial role in maintaining corneal transparency and hydration, and inflammation in this layer can lead to corneal edema and vision loss.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because keratic precipitates do not form on the corneal epithelium, which is the outermost layer of the cornea. The epithelium is a stratified squamous epithelium that provides a barrier against external pathogens and is not typically involved in the formation of keratic precipitates.
**Option B:** This option is incorrect because keratic precipitates do not form on the corneal stroma, which is the middle layer of the cornea. The stroma is composed of collagen fibers and keratocytes, and while it can be affected by inflammation, keratic precipitates specifically form on the corneal endothelium.
**Option C:** This option is incorrect because keratic precipitates do not form on the Descemet's membrane, which is a thin layer of collagen that separates the corneal stroma from the endothelium. While Descemet's membrane can be affected by disease processes, keratic precipitates specifically form on the endothelium itself.

**Clinical Pearl / High-Yield Fact**
In cases of anterior uveitis, the presence of keratic precipitates on the corneal endothelium can be a useful diagnostic clue. The distribution and density of keratic precipitates can provide information about the extent and severity of inflammation in the anterior segment of the eye.

**Correct Answer:** C.