Snow-blindness happens when a person is exposed to __________.

The correct answer is Option (3) → High UV-B dose

Option (3) High UV-B dose — Correct. UV-B is a band of ultraviolet radiation. It is absorbed by the cornea of the eye; a high dose, for example from sunlight reflected by snow, inflames the cornea, which is snow-blindness (cataract can also follow).

Note: This question is from Chapter 16, Environmental Issues, of the pre-rationalised NCERT book. This chapter is not in the present NCERT book (2026-27). The extract below is from the pre-rationalised edition.

NCERT Extract (Pre-rationalised edition, Chapter 16, Environmental Issues):
Ozone Depletion in the Stratosphere – “… UV radiation of wavelengths shorter than UV-B, are almost completely absorbed by Earth’s atmosphere, given that the ozone layer is intact. But, UV-B damages DNA and mutation may occur. It causes aging of skin, damage to skin cells and various types of skin cancers. In human eye, cornea absorbs UV-B radiation, and a high dose of UV-B causes inflammation of cornea, called snow-blindness, cataract, etc.”