**Core Concept**
Fungal corneal ulcers are a type of infectious keratitis caused by fungi, which can lead to vision loss if left untreated. The pathogenesis involves the invasion of fungal hyphae into the corneal tissue, leading to inflammation and tissue damage.

**Why the Correct Answer is Right**
Fungal corneal ulcers typically present with a characteristic 'feathery' or 'branching' edge, which is a result of the invasive growth of fungal hyphae. The most common causative organisms are Fusarium, Aspergillus, and Candida species. The diagnosis is often confirmed by corneal scrapings or biopsy, which are then examined under microscopy or cultured to identify the causative fungus. Treatment typically involves antifungal medications, such as natamycin, voriconazole, or amphotericin B, in addition to supportive measures like pain management and lubrication.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specify a characteristic feature of fungal corneal ulcers.
**Option B:** This option is incorrect as it is not a specific feature of fungal corneal ulcers, which can have a range of presentations.
**Option C:** This option is incorrect as it is a feature of bacterial corneal ulcers, not fungal corneal ulcers.

**Clinical Pearl / High-Yield Fact**
It is essential to differentiate fungal from bacterial corneal ulcers, as the treatment and prognosis differ significantly between the two. Fungal corneal ulcers often require prolonged treatment with antifungal medications and may have a higher risk of complications, such as vision loss or perforation.

**Correct Answer: C**