This document provides an overview of thin lenses, including diverging and converging lenses. It explains that diverging lenses are concave and cause light rays to diverge, while converging lenses are convex and cause light rays to converge. The document also discusses how diverging and converging lenses are used to correct nearsightedness and farsightedness, and how lenses are arranged in compound microscopes and telescopes. Finally, it poses several questions about thin lenses and lens applications.

1. Thin Lenses
By: Olivia and Noelia

2. Objectives: (Thin Lenses 14.2)
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Compare diverging and converging lenses
Relate concepts to eyeglasses and contact
lenses
Describe the positioning of lenses in
compound microscopes and telescopes

3. Introduction
Hey ya’ll, today we will be covering lesson 14,
section 2 over Thin Lenses. Hopefully by the
end of this lesson, you will better
understand…
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Thin Lenses
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Diverging and converging lenses
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Ray diagrams

4. Introduction Continued...
Hopefully ya’ll will also better understand…
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What type of lenses are used for the
correction of nearsightedness and
farsightedness
How lenses are positioned in
compound microscopes and
telescopes

5. Information
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Lenses use refraction, unlike mirrors that
use reflection.
Refraction is simply the bending of light as it
passes from one substance to another.
A lens forms an image by bending rays of
light that pass through it.

6. Diverging Lenses
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Also known as concave lens
These lens are thinner in the middle, causing
the rays of light to appear to come from a
single point
After light is passed through these lenses, it
bends and splits (diverges)

7. Diverging Lenses Continued...

8. Converging Lenses
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Also known as convex lens
These lenses are thicker in the middle,
causing rays of light that are initially parallel
to meet at a single point called the focal
point
After light is passed through these lenses, it
bends and comes together at one point
(focal point)

9. Converging Lenses Continued...

10. Ray Diagrams

11. Nearsightedness Correction
o When the eye is too
long.
o The focus point is in
front of the retina,
instead of sharply
being focused in.

12. Nearsightedness Correction
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To correct this problem
diverging lenses are
used.

13. Farsightedness Correction
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When the eye is too
short, and the focus
point is behind the
retina

14. Farsightedness Correction
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To correct this
problem converging
lenses are used

15. Compound Telescopes
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A telescope is an instrument made to make
distant objects appear nearer.
It contains an arrangement of lenses, by
which rays of light are collected
and focused and the resulting image
magnified.

16. Compound Microscopes
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A microscope is an instrument that is used
for viewing very small objects, such as
animal or plant cells, which are typically
magnified several hundred times.
A microscope has
two main lenses
(ocular and objective)

17. Questions
1) What is another name for diverging lenses?
Concave
2) How many lenses does a microscope have?
What are they called?
Two (ocular and objective)
3) What kind of lens are used to correct
farsightedness?
Converging
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18. Questions Continued...
4) Where is the focus point located on a nearsighted person’s eye?
In front of the retina
5) In order for a compound telescope to
produce an image, what kind of lenses must
be present?
Converging
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19. Questions Continued...
6) Which lenses makes light disperse after
being bent and passed through?
Diverging
7) True/False...Farsightedness people’s focus
point is located behind the retina?
True
8) Which instrument is designed to make
distant objects appear nearer?
A telescope
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20. Work Sited
staff, M. (2012, March 3). Definition. Mayo Clinic. Retrieved October 29, 2013, from
http://www.mayoclinic.com/health/nearsightedness/DS00528
staff, M. (2012, April 24). Definition. Mayo Clinic. Retrieved October 29, 2013, from
http://www.mayoclinic.com/health/farsightedness/DS00527
Diverging Lenses - Ray Diagrams. (n.d.). Diverging Lenses - Ray Diagrams. Retrieved October 29,
2013, from http://www.physicsclassroom.com/Class/refrn/U14l5ea.cfm
Converging Lenses - Object-Image Relations. (n.d.). Converging Lenses - Object-Image Relations.
Retrieved October 29, 2013, from http://www.physicsclassroom.com/Class/refrn/u14l5db.cfm
How a Compound Light Microscope Works. (n.d.). Compound Light Microscope: How It Works.
Retrieved October 29, 2013, from http://www.indepthinfo.com/microscopes/compound.htm