Question:easy
Photoretinitis is due to?
Photoretinitis is due to?
Show Hint
Think of the classic warning against looking directly at an eclipse.
Updated On: Jun 24, 2026
- Snow reflection
- Solar eclipse
- Blunt trauma
- None of the above
Show Solution
The Correct Option is B
Solution and Explanation
Step 1: The question asks which exposure injures the retina by light. Photoretinitis = a macular burn produced when the eye fixates on a bright source, the commonest real-world example being eclipse viewing.
Step 2: Mechanism is photochemical, not thermal. Energy in the blue/violet-blue band of visible light (roughly $400$ to $500$ nm) plus some UV-A drives oxidative damage at the fovea. This is why it carries the name blue-light retinal injury, and why earlier belief that infrared was responsible is incorrect.
Step 3: Eliminating the other options - snow reflection produces ultraviolet keratitis affecting the cornea, and blunt trauma produces commotio retinae or choroidal rupture through mechanical force. Neither is a light-driven foveal photochemical lesion.
Step 4: Symptoms include a lasting after-image, central positive scotoma and distorted vision, matching a foveal photochemical burn from eclipse gazing.
\[\boxed{\text{Solar eclipse}}\]
Step 2: Mechanism is photochemical, not thermal. Energy in the blue/violet-blue band of visible light (roughly $400$ to $500$ nm) plus some UV-A drives oxidative damage at the fovea. This is why it carries the name blue-light retinal injury, and why earlier belief that infrared was responsible is incorrect.
Step 3: Eliminating the other options - snow reflection produces ultraviolet keratitis affecting the cornea, and blunt trauma produces commotio retinae or choroidal rupture through mechanical force. Neither is a light-driven foveal photochemical lesion.
Step 4: Symptoms include a lasting after-image, central positive scotoma and distorted vision, matching a foveal photochemical burn from eclipse gazing.
\[\boxed{\text{Solar eclipse}}\]
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