Snow blindness is caused by
**Core Concept**
Snow blindness, also known as ultraviolet keratitis, is a condition that occurs when the cornea is exposed to intense ultraviolet (UV) radiation from snow or ice. This damage leads to inflammation and pain in the eyes.
**Why the Correct Answer is Right**
The correct answer involves the absorption of UV radiation by the cornea, which activates the arachidonic acid pathway, leading to the release of pro-inflammatory mediators such as prostaglandins and leukotrienes. These mediators cause vasodilation, increased permeability, and edema, resulting in snow blindness. The cornea's avascular nature makes it particularly susceptible to UV damage.
**Why Each Wrong Option is Incorrect**
* **Option A:** Not relevant to snow blindness. While UV radiation is a key factor, the condition is not caused by a lack of vitamin A.
* **Option B:** Not directly related to snow blindness. While UV radiation can cause damage to the skin, it is not the primary cause of snow blindness.
* **Option C:** Not accurate. Snow blindness is not caused by a viral infection, but rather by physical damage from UV radiation.
**Clinical Pearl / High-Yield Fact**
Snow blindness is often referred to as "winter's snow blindness" and can be prevented by wearing protective eyewear that blocks UV radiation, such as sunglasses or goggles.
**Correct Answer:** C.