Human Eye & Colourful World: Vision & Light Phenomena

Grade 9 Science — Human Eye & Colourful World: Vision & Light Phenomena: 25 practice questions with instant scoring and explanations.

1. The part of the eye that controls the amount of light entering is the:
2. The lens in the eye focuses light onto the:
3. Myopia (short-sightedness) is caused by:
4. A person with myopia has difficulty seeing:
5. Myopia is corrected using:
6. Hypermetropia (long-sightedness) is caused by:
7. Hypermetropia is corrected using:
8. Presbyopia occurs due to:
9. Astigmatism is due to:
10. The power of a lens is measured in:
11. A lens has power P = 2 D. Its focal length is:
12. Dispersion of light is the:
13. A prism disperses light because:
14. The color that deviates the least in a prism is:
15. A rainbow forms due to:
16. The order of colors in a rainbow from outer to inner arc is:
17. Atmospheric refraction causes:
18. The Tyndall effect is:
19. The sky appears blue because:
20. The sun appears reddish at sunrise and sunset because:
21. The photoreceptors in the retina responsible for color vision are:
22. Color blindness in humans is often related to:
23. Total internal reflection occurs when light travels from:
24. Critical angle for glass-air interface is approximately:
25. Optical fibers work on the principle of: