Look Who it Was Random video

Human Eye - Lenses (Part 5)

1,934 views · Published 9 October 2016 · 22:04 · Indexed 7 October 2026

Channel: Meritstore - Online Learning · 2016 · Education

Watch on YouTube

Subscribe to our channel for More http://tinyurl.com/zyx92ab

For more such video lectures, visit : https://www.meritstore.in/lesson/basic-concepts-of-std-x/
___________________________________
Don't forget to ask us questions in the comments section below.
1. What is cornea?
2. What is iris?
3. What is pupil?
4. State the function of the iris in the human eye.
5. What is the use of the pupil in the human eye?
6.  With reference to the functioning of the pupil in the human eye, what is adaptation?
7. What is the shape and the size of the human eyeball?
8. Name the part of the human eye that forms a transparent bulge on the surface of the human eyeball 
9. Which part of the human eye is located just behind the pupil?
10. What is retina?
11. What does the eye lens do?
12. What happens when light falls on the retina?
13. What are ciliary muscles?
14. What is the focal length of the eye lens of a normal eye in relaxed position of eye muscles?
15. Where does the second focal point of the eye lens of a normal eye in relaxed position of eye muscles lie?
16. State the function of ciliary muscles in the human eye.
17. Explain the function of ciliary muscles in the human eye.
18. What is meant by power of accommodation of the eye?
19. Explain the term power of accommodation of the Eye. Or write a short note on the power of accommodation of the eye
20. What is meant by accommodation? How is it brought about? 
21. What is meant by the distance of distinct vision?
22. Explain the term distance of distinct vision. 
23. State four reasons related to problems of vision.  – Problems of vision are related to (i) weakening of ciliary muscles (ii) change in the size of the eyeball (iii) irregularities on the surface of cornea  (iv) formation of a membrane over the eye lens.
24. What is myopiya or near-sightedness?  What are the possible reasons of myopia?  How is myopia corrected?  Explain with diagrams.
25. What is the sign of the power of the lens used to correct myopia?
26. In a Std. X class, out of 40 students, 10 students use spectacles, 2 students have positive power and 8 students have negative power of lenses in their spectacles.
27. What is hypermetropia?  What are the possible reasons of hypermetropia?  How is hypermetropia corrected?
28. What is the sign of the power of the lens used to correct hypermetropia? – The power of the lens  used to correct hypermetropia is positive.
29. What is presbyopia?  State the reason for this defect.  How is presbyopia corrected?
30. What is a bifocal lens?
31. A biofocal lens is a lens of which the upper part is a concave lens to correct myopia and the lower part is a convex lens to correct hypermetropia.
32. (A) Anil cannot see the blackboard writing clearly, but he can see nearby objects clearly. (i) What is the eye defect he is suffering from? (ii) How is it corrected? (B) Anil’s uncle cannot see nearby objects clearly,  but he can see distant objects clearly. (i) What is the eye defect he is suffering from?  (ii)  How is it corrected?
33. When are bifocal lenses used in spectacles?
34. Anita from Std. X is using spectacles.  The power of the lenses     
in her spectacles is – 1 dioptre. (1) Which lenses are used in her spectacles? (2) State the defect of vision Anita is suffering from. (3) Find the focal length of the lenses used in her spectacles.
35.  Sunita from Std. X is using spectacles. Her spectacle number is -1.5. (a) Name the defect off eye from which she is suffering. (b) What type off lens is she using? (c) Find the focal length of the lens.
36. Sunita from Std. X uses spectacles.  the power off the lenses in   her spectacles is 0.5 dioptre. (1) State the type of lenses used in her spectacles. (2) Name the defect of vision Sunita is suffering from. (3) find the focal length off the lenses used in her spactacles.
 37. My grandfather uses a bifocal lens in his spectacles.. Explain Why.
38. Name four optical devices or instruments in which convex lenses are used.



Website    ► http://www.meritstore.in/
Facebook ► https://facebook.com/meritstore.in
Twitter      ► https://twitter.com/meritstore
Blog          ► http://www.meritstore.in/posts

More from this channel