A sample lesson plan about lenses.

1. A Semi-detailed Lesson Plan
in Science and Technology 4
Prepared by Randolph Domingo Jr.
I. Learning Objectives II. Learning Content III. Learning Procedure IV. Evaluation V. Assignment
Through experiential A. Subject Matter: A. Preparation See strategies number On a one whole sheet of
activities using lenses, Lenses two, four, six and eight ofpad paper, write a short
the students should 1. Review the Presentation Portion reflection on the
be able to: B. References: a. Group the class into pairs or into threes. of the Learning Procedure. importance of lenses in our
b. Give the different groups the following lives. Make your
A. devise the Microsoft ® Encarta ® materials: assignment substantive as
characteristics and 2009. © 1993-2008 a. Fishbowl filled with water up to the See strategy number three short as possible. This will
properties of a Microsoft Corporation. brim. of the Application portion be passed on January 24,
convergent and All rights reserved. b. Small piece of colored paper of the Learning Procedure. 2013 (Thursday). This
divergent lens; c. Two lenses assignment is worth 20
www. opticalres. com points. Please by guided by
B. apply the principles c. Present the instructions of the activity the following rubrics:
of Image formation in www.hyperphysics.com
finding the suitable 1. Measure the dimensions of the given Content: 10 points
lens to correcting eye colored paper using a foot rule. Neatness: 6 points
defects. C. Materials 2. Let the colored paper stand at one side Punctuality: 4 points
of the fishbowl. Gaze at the colored paper
C. value the 1. 3 Magnifying on the other side of the fishbowl. Notice - Lenses are very
importance of lenses glasses and estimate the size of the colored important. They help
in eye defect 2. 3 Divergent Lenses paper. correct eye defenses such
correction through a 3. 3 Fishbowls as myopia, Hyperopia, and
group activity; and 4. 3 Bottles of Water d. Give the set of questions to the different astigmatism. Furthermore,
5. Small pieces of groups. lenses are used in our
D. construct a diagram colored paper 1. What changes did you notice when you modern day technology to
on image formation 6. Schematic model of viewed the colored paper through the fishbowl? investigate the world
correctly based on the a convergent and - The colored paper became larger beyond ours. Telescopes,
principles of image divergent lens 2. What concept was applied in this binoculars, help us
formation. 7. Schematic model of activity? appreciate the stars and
a myopic and hyperopic - Refraction was applied here. bodies around Earth.
eye ball 3. What is Refraction ?
8. 3 arrows - Refraction is the bending of light as it
9. 3 dotted lines enters a different medium.
10. Letter Markers 4. Where do we see Refraction in our lives?
11. Pictures of Lenses - We see refraction when we put a spoon in a
12. Comic Strips glass of water, in eye glasses, and magnifying

2. about lens glasses.
D. Concepts 2. Motivation
1. Lens- A glass or a. Give the students a trivia
other transparent
Did you know the ancient Greeks used
substance so shaped
spherical glasses to burn objects?
that it will refract the
light from any object b. Pose the following questions
and form a real or 1. Why did the Greeks use a spherical glass
virtual image. filled with water to burn things?
2. Convergent Lens- A - Because water filled spherical glass
convergent lens is concentrates light into a single point.
thicker at the center Concentrating light to a single point causes heat,
and thinner at the consequently causes burning.
edges. It magnifies the 2. Could we use the materials in the activity
object being seen if it is done earlier as burning glasses too? Are they
near the object. practical to use? What is much better to use?
Convergent Lenses are - Yes, we could use these materials as
named so because they burning glasses but they aren’t practical to use
unite refracted light since they are hard to carry. A more practical
rays at one point. This object to use is the lens.
is true because they are
thicker at the center B. Presentation
and thinner at the
edges. 1. Present the definition of lens and its two
3. Divergent Lens- classifications through a power point.
Divergent lenses are
thinner at the center Lenses
and thicker at its edges. A glass or other transparent
It often creates a substance so shaped that it will
diminished image of refract the light from any object
the object when looked and form a real or virtual image.
through upon this kind
of lens. They are named Convergent Lens Divergent Lens
divergent lens because Lenses having a Lenses having a
they diverge light rays. convex surface concave surface
4. Principal Axis- This
is the line that is drawn 2. Present an activity 1 using real convergent
through the centers of lens which is done by group.
curvature of both a. Feel the lens. Observe what region of the

3. spherical surfaces. lens feels thicker and thinner.
5. Focal Point- b. Look at your pair through the lens. Make
Portion where a beam sure you get a good clear view of you partner.
of light parallel to the c. Pose the questions
principal axis 1. What did you observe?
converges. - This lens is thicker at the center than at
6. Focal Length- This the edges. When we looked at our pair, the image
is the distance between was magnified.
the center of the lens 2. What type of lens is this?
and its focal point. - This lens is a Convergent lens.
7. Focal Plane- This is
the area that covers all 3. Discuss the characteristics and properties of a
the points above and Convergent Lenses through a picture analysis of a
below the principal convergent lens.
axis.
8. Image formation:
Convergent Lens:
a. A ray parallel to the
principal axis is
refracted to pass
through the focal point.
b. A ray that passes
through the center of
the lens passes through A convergent lens is thicker at the center
undeflected. and thinner at the edges. It magnifies the
c. A ray that passes object being seen if it is near the object.
through the focal point Convergent Lenses are named so because
of the lens is refracted they unite refracted light rays at one
parallel to the principal point. This is true because they are thicker
axis. at the center and thinner at the edges.
Divergent Lens:
a. A ray parallel to the 4. Give activity 2 using real divergent lens which
principal axis is is done by group.
refracted as though it a. Follow the procedure that was done
comes from the focal during the first activity but use the second lens
point. instead of the first one.
b. A ray that seems to b. Pose the questions
come from the focal 1. What did you observe when you used
point of the lens is the lens?
deflected parallel to the - The image formed is diminished and it

4. Principal axis. thinner in the center than the edges.
c. A ray that passes 2. What lens is this?
through the focal point - This lens is a Divergent lens.
of the lens is refracted
parallel to the principal 5. Discuss the characteristics and properties of a
axis.
E. Skills
1. Observing skills
from inferring the
characteristics of a
Convergent and
Divergent lens.
2. Analyzing the Divergent lens through a picture analysis of a
different observations divergent lens.
to devise the properties
and characteristics of Divergent lenses are thinner at the center
lenses. and thicker at its edges. It often creates a
diminished image of the object when
F. Values looked through upon this kind of lens. They
1. In union there is are named divergent lens because they
strength. diverge light rays.
2. Appreciating the
values of lenses in eye 6. Present activity 3 using a convergent lens.
defect correction in the a. Using the convergent lens, view your
activity "Finding which partner through it at the level of your arm chair.
Lens to what Eye". Both you and your partner should bend down to
get a good view at each other.
b. Find the point where the image is the
clearest. Mark that point and measure the
distance it is away from your eyes. Your partner
should find this point at the other side of the
lens.
c. Pose the following questions
1. What is the distance that you measured
for both sides? Are they the same?
- The distance is about 4- 5 cm.

5. 7. Present the discussion of the Anatomy of the
Lens by posting a picture of it.
Principal Axis- This is the line that is drawn
through the centers of curvature of both
spherical surfaces.
Focal Point- Portion where a beam of light
parallel to the principal axis converges.
Focal Length- Distance between the center
of the lens and its focal point.
Focal Plane- This is the area that covers all
the points above and below the principal
axis.
8. Give the rules of Image formation by lenses
through an interactive discussion and a game.
a. Give the students the following materials
a.1. 3 arrows
a.2. Schematic lens diagram model of a
Convergent and Divergent lens
a.3. Dotted Lines
a.4. Letter markers
b. Present the diagram of each rule of image
formation after each rule is stated.
b.1. Present the rules of Image formation
for a convergent lens
1. A ray parallel to the principal axis is
refracted to pass through the focal point.
2. A ray that passes through the center of
the lens passes through undeflected.
3. A ray that passes through the focal point
of the lens is refracted parallel to the
principal axis.

6. b.2. Present the rules of Image formation for
a Divergent lens through an interactive
discussion.
1. A ray parallel to the principal axis is
refracted as though it comes from the
focal point.
2. A ray that seems to come from the focal
point of the lens is deflected parallel to the
Principal axis.
3. A ray that passes through the center of
the lens passes through undeflected.
C. Application
1. Post pictures about people having the eye
defects Myopia and Hyperopia then present
questions about the comic strip.

7. a. What does the pictures shows?
- The picture shows people reading
differently than normal.
b. What is wrong with them?
- These people have the eye defect Myopia
and Hyperopia.
2. Discuss Myopia and Hyperopia through
showing pictures of eyeballs depicting these eye
defects.
Myopia is also called as near sightedness.
Myopia is either acquired or genetic. We
acquire Myopia as we age. Myopia is
genetically transferred from parent to
offspring. It occurs when the eyeball is
longer than normal, thus the image formed
is formed before the retina. This defect
could be corrected using an eye glass.
Hyperopia is called as far sightedness.
Hyperopia is genetic in nature. It occurs
when the eye ball is shorter than normal,
thus the image is formed beyond the
retina. Like Myopia, it could also be
corrected by an eye glass.
3. Give the activity “Finding which Lens to what
Eye” through giving its instructions

8. Find out which lens is needed to correct
the mentioned eye defects by applying the
principles of image formation. Given a
schematic model of a myopic and
hyperopic eye, try to create a ray diagram
using the given rays and dotted lines. Try to
let the image fall on the retina of the eye
model. Once you have determined what
lens correct what eye defect, write your
answers on a ¼ sheet of pad paper.
a. Pose the following questions
1. What lens is used to correct Myopia? How
about Hyperopia?
- A convergent lens is used to correct
farsightedness and a divergent lens is used to
correct nearsightedness.
2. How do lenses correct these eye defects?
- These lenses either converges or diverges
light rays before entering the eye’s lens. This
makes the image form on the eye’s retina.
3. Are lenses important? How?
- Lenses are important. They are used to
help people with eye defects. They correct eye
defects like Myopia and Hyperopia.
Generalization
1. Post a Comic Strip about lenses.
Oh my! Where are my glasses?

9. 2. Pose the following questions
1. What is the comic strip all about?
- It shows the character Velma trying to
find her glasses.
2. What are eyeglasses? Expound on your
answer.
- Eyeglasses are lenses. Lenses are glasses
that are used to refract light. There are two types
of lenses, divergent and convergent lenses.
The first one is used to scatter light waves and the
latter is used to converge light to one point.
3. How do lenses help correct eye defects?
What is the principle behind it?
- These lenses either converges or diverges
light rays before entering the eye’s lens. This
makes the image form on the eye’s retina. Lenses
use the principle of image formation.
4. What is the importance of lenses?
- Lenses are important to people suffering
from eye defects. They correct eye defects so the
person could appreciate the world. Also, they let
us appreciate the world around us and let us see
things that the eye couldn’t normally see.