AInflammation of cornea due to high dose of UV-B radiation
BHigh reflection of light from snow
CDamage of retina caused by infra-red rays
Dfreezing of fluids in the eyes by low temperature
Answer:
A. Inflammation of cornea due to high dose of UV-B radiation
Read Explanation:
Understanding Snow Blindness (Photokeratitis)
Definition: Snow blindness, also known as photokeratitis, is a temporary but painful eye condition caused by overexposure to ultraviolet (UV) light.
Cause in Antarctic Regions: The Antarctic region presents a unique and intensified risk for snow blindness primarily due to the high reflectivity of snow and ice, which can reflect up to 80% of UV radiation. This significantly amplifies the UV dose reaching the eyes.
Specific UV Radiation: The primary culprit is UV-B radiation. While UV-A penetrates deeper into the skin, UV-B has higher energy and is more damaging to the surface tissues of the eye, particularly the cornea.
Mechanism of Damage: UV-B radiation causes inflammation of the cornea (the transparent outer layer of the eye). This inflammation is similar to a sunburn on the skin, affecting the surface cells of the cornea.
Symptoms: Common symptoms include intense eye pain, redness, a gritty sensation, sensitivity to light (photophobia), blurred vision, and excessive tearing. Symptoms typically appear several hours after exposure.
Risk Factors in Antarctica:
High Altitude: Higher altitudes generally have less atmospheric filtering of UV radiation.
Reflectivity of Snow and Ice: As mentioned, snow and ice act like mirrors, bouncing UV rays back and increasing exposure.
Clear Skies: While Antarctica can have clouds, periods of clear skies allow for maximum UV penetration and reflection.
Lack of Shade: The vast, open icy landscapes offer little to no natural shade.