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? 發問於 科學及數學化學 · 1 十年前

~about sunglasses

1.some dark-coloured sunglasses cannot cut off ultra-violet light.

Why ewearing such sunglasses under bright sunlight would be more damaging to the eye that not wearing any sunglasses.

*THANKS.

1 個解答

評分
  • 1 十年前
    最愛解答

    It is because wearing sunglasses will provide a darker environment for the eyes.

    In dim light, the radial muscles of the iris contract and the circular musclesrelax. The pupil becomes larger in size (dilates) and more light is allowed to pass through the lens and go to the retina.

    As more light is allowed to pass to the retina, the photosensitive cells may be over-stimulated (due to excess ultra-violet light) and may be damaged. So, wearing such kind of sunglasses under bright sunlight would be even more damaging to the eye than not wearing any sunglasses.

    資料來源: Myself~~~
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