Q. 74 B
What is night blindness? What causes night blindness?
Answer :
Night blindness is the inability to see properly at night or in poor light. In scientific terms, it is called as "nyctalopia".
The following factors cause night blindness:
1) The deficiency of Vitamin A (retinol) in the diet of a person for a considerable time can lead to the disease called night blindness.
2) The disorder in which the rod cells in the retina gradually lose their ability to respond to the light.
3) It can also happen due to cataract, or clouding of the eye’s lens.
4) Usher syndrome can also cause night blindness, which is a genetic condition that affects both hearing and vision.
5) Nearsightedness or blurred vision can also cause night blindness.
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