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Asia-Pacific Forum
on Science Learning and Teaching, Volume 15, Issue 1, Article 5 (Jun., 2014) What do the prospective science teachers know about human eye? |
The findings obtained from the word associated test
According to the result of the WAT, the detailed frequency table of the created networks is presented in the Appendix 1. The PSTs’ numbers of answer words about keywords “human eye, human eye defects, its treatments, vision are presented in the Table 1:
Table 1. The numbers of the PSTs’ first three answer words according to cut-off points and their total answer words
The keywords
Numbers of the total answer words (N=34)
The PSTs’ the answer keywords
14-up Cut-off point
7-14 Cut-off point
0-7 Cut-off point
Human eye
42
Fovea
30
Myopia
21
Hypermetropia
19
Human eye defects
13
Myopia
22
Hypermetropia
21
Astigmatism
18
The treatment of human eye defects
15
Operation
19
The concave lens
17
The convex lens
16
Vision
27
Fovea
11
Human eye
8
Optic nerves
8
In the Table 1 it is seen that the PSTs stated the most often the fovea, myopia, hypermetropia for human eye keyword in the first three. The PSTs stated the most often the myopia, hypermetropia and astigmatism words for human eye defects keyword. According to cut-off point 14-up, the PSTs stated the most often fovea word for both human eye and vision keywords. The PST stated as answer “human eye” keyword for “vision” keyword. They associated human eye with vision words.
Figure 1. According to the results of the WAT is first and maximum connection, preparing the networks (Cut off point 14- )
When Figure 1 was examined it is seen that the PSTs associated human eye and its defects keywords. The PSTs stated words are operation, the convex and concave lenses and no treatment for “the treatments of human eye defects” keyword. It is seen that the PSTs did not stated any word for “vision” keyword at the 14-up cut-off point.
When Figure 2 was examined it is seen that the PSTs associated “human eye” and “vision” keywords. The PSTs stated word is cylinder lens for “the treatments of human eye defects” keyword. PSTs stated words are the presbyopia, cataract and glaucoma for “human eye defect” keyword among 7-14 cut-off point.
In the Figure 2, repeated words in the first cut-off point (14-up) was symbolized with black, repeated words in the second cut-off point (7-14) was symbolized with red.
Figure 2. According to the results of the WAT is second and medium connection, preparing the networks (Cut off point 7-14)
In the Figure 3, repeated words in the first cut-off point (14-up) was symbolized with black, repeated words in the second cut-off point (7-14) was symbolize with red and repeated words in the third cut-off point (0-7) was symbolized with green.
When the third cut-off point was examined it is seen that the PSTs stated the mostly words related to the structure of human eye, vision, the auxiliary bodies, human eye defects and its treatments words in the third cut-off point. Also in the third cut-off point it is seen that the PSTs associated all of the keywords with each other.
Figure 3. According to the results of the WAT is the lowest connection, preparing the networks (Cut-off point 0-7)
The findings obtained from the open ended questions
Table 2. The frequencies of the findings obtained from the responses of the PSTs about the structure of human eye and the quotes from their views
Questions
T
PT
AC
B
The quotes from expressions of the PSTs which consisted of Alternative Concepts (AC)
Q1. Which are layers in the structure of human eye?
23
2
9
-
Front, middle, rear layers.
Q2. What is the function of these layers?
3
11
9
11
It has a function such as refracting light.
The nervous layer nourishes the eye.
Q3. Where is cornea? What is the function of the cornea?
14
3
9
8
The cornea allows seeing.
Q4. Which layer underwent a change and formed cornea?
8
-
17
9
Occurs by a change of the nervous layer.
Q5. Where is iris located? What is the function of iris?
5
10
14
5
It is located in the outermost layer.
It is found in nervous layer. It is below the nervous layer.
Iris gives color to human eye.
Q6. Which layer underwent a change and formed iris?
6
-
19
9
It was formed with the change of the cornea.
It was formed with the change of the outermost layer.
It was formed with the change of the nervous layer.
Q7. Where is the pupil located? What is the structure of the pupil like?
2
13
11
8
It is behind the ocular lens.
It is in the nervous layer.
Q8. What is the reason for the pupil’s being black with everyone?
4
10
5
15
Black absorbs light better.
To differentiate dark and light colors
Q9. What is the factor which is effective for the pupil to be sometimes small and sometimes large?
24
7
2
1
It expands when you get a fright.
Q10. In what area of human eye is the crystalline lens located?
4
4
19
7
It is between the iris and the pupil.
It is located in the outer layer.
It is found on the pupil.
It is between the cornea and the iris.
Q11. What kind of lens is crystalline lens? Why? Please explain.
18
-
9
7
It is a concave lens.
Q12. What is the function of crystalline lens? Please explain.
8
15
5
6
It absorbs light and it enables its transfer to the fibrous-nervous- vascular layer and bind spot.
Q13. Where is blind spot located?
23
-
4
7
It is behind the eye, above the fibrous layer.
Q14. Where is fovea located?
11
9
9
5
It is located in the posterior chamber of human eye.
Q15. How does vision occur? Which way is light follow when light entered human eye?
7
2
21
4
“Cornea, iris, crystalline lens, pupil, blind spot”
“Cornea, crystalline lens, pupil, yellow spot, blind spot”
In Table 2 are shown that the frequencies of the responses of the PSTs about the structure of human eye, the functions of these parts and the way the light follows during vision. It was revealed from the quotations of the PSTs that their explanations consisted of insufficient knowledge in the each question. The PSTs mostly could not answer the questions which were about the reason why the pupil is black with everybody, and what kind of lens is crystalline lens.
Table 3. The frequencies of the findings obtained from the responses of the PSTs about human eye defects and its treatment
The defects of human eye
Description of human eye defects
(N=34)
The treatment of human eye defect
(N=34)
T
AC
B
T
AC
B
Hypermetropia
22
10
2
20
12
2
Myopia
22
11
1
22
12
-
Astigmatism
23
4
7
9
6
19
Diplopia
20
8
6
15
3
16
Presbyopia
15
4
15
8
6
20
Color blindness
31
2
1
25
2
7
Cataract
4
14
16
18
3
13
Lazy eye
4
14
16
18
3
13
Daltonism
3
-
31
1
-
33
Glaucoma
2
1
31
-
-
34
Trachoma
-
1
33
-
-
34
When Table 3 is examined, while the PSTs were describing human defects as myopia, hypermetropia in this parallel they could answer the treatment methods of human eye defects at the same rate. But they could not answer the question about human eye defects such as trachoma and glaucoma.
The findings obtained from the PSTs' drawings
The findings obtained from the PSTs’ drawings were presented at below.
Table 4. The findings obtained from the PSTs’ drawings about human eye defects and its treatment
The themes of the PSTs’ drawings on human eye defects and its treatments
Drawings of human eye defects (N=34)
Hypermetropia
Myopia
TD
Human eye defects were drawn by the PSTs.
10
10
The treatments of human eye defects were drawn by the PSTs.
10
10
AD
The hypermetropia and myopia defects was confused by the PSTs.
6
6
The concave lens and convex lens were confused for the treatments of the eye defects.
4
4
Beams were not draw, but the location and image of the object were drawn correctly.
1
1
Beams were not drawn; also the image of the object was drawn incorrectly.
2
2
Beams were drawn according to breaking rule at the lens.
3
3
The image of the object was drawn straight on the fovea.
8
7
The image of the object was drawn in front of the fovea without use of the beams.
1
2
The image of the object was drawn behind of the fovea without use of the beams.
2
The lenses were drawn for treatments of the eye defects without use of the beam.
4
4
The images of the object were not drawn on the fovea for the treatments’ drawings of the eye defects.
2
2
There is no any drawing.
5
3
The image of the object is in front of the fovea and is straight.
1
2
The image of the object is behind of the fovea and is straight.
1
After than refraction of the beams at the lens it was drawn on the blind spot.
1
1
The lenses were not drawn for the treatments of the eye defects, only the names of these lenses were written on the figure.
2
2
The treatments drawings are incorrect.
2
2
The shapes of these lenses are not clear.
1
1
Just 10 PSTs could draw myopia, hypermetropia eye defects and its treatments correctly. The drawings exemplifying statements were presented at the Figure 4:
Figure 4. The true drawing of the PSTs
When was examined in the Figure 5, it is seen that the some PSTs confused hypermetropia and myopia eye defects. They drew instead of myopia hypermetropia. The quotations of the PSTs’ drawings were presented at the Figure 5.
Figure 5. The false drawing which the PSTs confused the hypermetropia, myopia eye defects and its treatments
In the Figure 6 is seen that the mistakes in the PSTs’ human eye defects drawings stems from not only the location of the image according to fovea but also drawing of the lenses and do not knowing of the refraction laws in the lenses. These findings related with an example of drawing are presented at the Figure 6:
Figure 6. The image is straight and the usage of these lenses is incorrect for the treatment of the eye defects
Figure 7. The alternative drawing of the PSTs
In the Figure 7 is seen that image is straight in the behind and in front of the fovea, whereas the image must be inverse. For the treatments of human eye defects, the lenses were selected correctly but light beams were not drawn. Although the image of object is straight, the location of image is correct.
The findings obtained from the one two tiered-question
The findings obtained from the PSTs’ answers to the two-tiered question were presented at below. Question: A mosquito bites Ahmet’s chin at midnight. Ahmet wants to see where the mosquito has bitten. Ahmet immediately finds a flashlight and mirror. If he wants to see his chin in the mirror very clearly. How should he hold the flashlight?
A) He should hold the flashlight to the mirror.
B) He should hold the flashlight to his chin.
C) He should hold the flashlight parallel to the mirror.
D) He should hold the flashlight straight to the mirror.
E)……………………………………………………………………………………..
Qii. Which one of the diagrams below perfectly explains your idea? If none of the diagrams explains your ideas. Draw your diagram in the box E.
When were examined answers of the PSTs related with two-tiered question, 13 PSTs stated that it is necessity Ahmet should hold the flashlight to his chin for seeing where the mosquito has bitten. But only 2 PSTs could draw the second phase of the question correctly. The drawings exemplifying statements were presented at below:
Figure 8. The true drawing of the PST
Figure 9. The selection of the other PSTs
Twenty one PSTs stated that these statements are incorrect such as Ahmet should hold the flashlight to the mirror, the flashlight parallel to the mirror, the flashlight straight to the mirror for seeing where mosquito has bitten. In parallel of this case, they marked false to the second phase of this question.
“How the image of the object is formed among focus of peak in the convex lens? Please draw.” drawing question only 1 PST could draw correctly. But he stated that image of object formed at infinity we cannot see it. Also he did not draw vision, he could draw image in the convex lens. The other PSTs drew the image of object incorrectly. The examples of the PSTs’ drawings were presented at the Figure 10 and 11.
Figure 10. The alternative drawings of the PSTsThe selection of the other PSTs
Figure 11.The drawing is insufficient and the explanation of the PST is false
The findings obtained from the interview about concepts
The findings obtained from the interviews conducted with the selected 10 PSTs with were presented at below:
Table 5. The findings obtained from the interview about human eye concept
Themes
The PSTs and categories of their answers
The Alternative concepts of the PSTs
T
PT
AC
The vision in the Myopia and Hypermetropia
D, E, F, G, H, I, J
-
A, B, C
1. “Someone has hypermetropia cannot see distant clearly. Someone has myopia cannot see near clearly” (A,B,C)
2. “The crystalline lens acts as a concave lens.” (A,I)
According to the fovea, the location of the image
A, D, E, F, G, H, J
-
B, C, I
3. “The concave lens was used for treatment of the hypermetropia and the convex lens was used for the treatment of the myopia.” (B,I,J)
The selection of the lens for treatment of human eye defects
A, D, E, F, G, H, J
-
B, I
4. “The cause of the hypermetropia and myopia may be caused from the problem in the pupil.” (C)
5. “The myopia can be caused from contraction of the eye muscle at the behind. If the eye muscle in the behind is long may cause to hypermetropia.” (D)
The causes of the myopia and hypermetropia eye defects
-
F, G, H
A, B, C, D, E, I, J
6. “The cause of the hypermetropia and myopia may be caused from the problem in the cornea.” (E)
7. “The eye is swollen in the myopia and principal axis is extended, in the hypermetropia principal axis is extended.” (I)
8. “In my opinion the pupil is a structure as head of fastener. I surprised when saw the pupil is space in the middle of the iris.” (D,F,H,I,J)
When Table 5 was examined is seen; although A coded PST stated the location of the image and using lens for treatment of the eye defect correctly, but he stated the cause of the eye defect and vision problem which myopia cannot see near incorrectly.
I coded PST stated the problem of the eye defect which cannot see near/distance correctly, but he stated the location of the image, using lens for treatment of the eye defect and the cause of the eye defect incorrectly.
F, G, H coded PSTs stated the eye defect, the vision problem, the location of the image and using lens for its treatments correctly. They explained the causes of the eye defects partially correct. The statement of G coded PST “...the refractive index of the crystalline lens is disrupted and the image occurs in different places from the fovea. The flexibility of muscles in the crystalline lens may be disturbed. It may cause from congenital. The crystalline lens swells and its refractive increases...” is example to the partial correct explanation.
PSTs stated 1 and 3 numbered alternative concepts often in the Table 5. The PSTs confused myopia with hypermetropia each other. For example; B coded PST stated as “Someone has hypermetropia cannot see distant. The image form in front of the fovea, for reaching to the fovea of the image is necessity the light beams must be fracture with concave lens removing. The cause of the hypermetropia is that refractive index of the crystalline lens is higher than normal. Someone has myopia cannot see near. The image form in the behind of the fovea, for focusing to the fovea of the image must be used convex lens. The cause of the myopia is that refractive index of the crystalline lens is thinner than normal. So refractive index of the crystalline lens is lower than normal.”
Table 6. The learning difficulties of the PSTs obtained from the interview about human eye concept
Themes
According to the PSTs, The Understanding Difficulties of the PSTs
The PSTs
To confuse
“I confused because Latin is called myopia and hypermetropia, I'm drawing the first shape I remembered.”
A, E, I
To Memorize
“I do not memorize the names of its”
B, C, I
" I forget what I memorized because I do not repeat continuously"
C
“I do not memorize the vision, the ray of the light follow”
H
To be unrelated
“I have no interest in physic. I'm trying to memorize how refracting occur in lenses, but then I forget it”
C
To associate interdisciplinary
C,
To draw
“I know that the image occur in front of the fovea, image is reverse, but I do not draw to image. I have problem in the drawing.”
D, I
To establish cause-effect relationship
“I know the eye defects, but I do not know the cause of the eye defects. So I'm having trouble, I do not associate to different case.”
F, I
To use language
“The words are different in daily usage of language life may cause to learning disability.”
G
To understand human eye structure
“I do not distinguish the fovea, blind spot and vitreous body.”
B
“I confused which layer underwent a change and formed cornea, retina or fibrous layers”
B
“Although the crystalline lens is same objects, how it perceives different objects at different distances? This I do not understand.”
B
“We say the vision of the objects is related to the pupil, the pupil grows and shrinks it adjusts the amount of light. What is the task or relevance of the lens for occurring of the image? I do not understand”
B
“I confuse and use instead iris of retina.”
H
“I do not memorize the vision, ray of the light follow”.
H
“I do not know human eye structure exactly.”
H, I
“Do not anything in the pupil? What is anything else in the blind spot? Only do nerves walk out form the blind spot?”
J
G coded PST stated that he has no problem with his statement as “I have no problem I’m learning associating with lenses. Also I have the myopia defects, so I do not forget it...” J coded PST stated that she has no any problem with her statement as “Before I do not remember which lens used for treatment of the eye defects. But my brother told a codification “KUM”(Turkish means of KUM is sand in English) code are “K” the concave lens (concave lens is read as Konkav lens in Turkish), “U” cannot see distance (means of distance is as Uzak in Turkish), “M” Myopia eye defect (myopia is read as miyop in Turkish). Also, the name of hypermetropia is long and the image occurs in the behind of the fovea. I coded as that.”
Table 7. The suggestions of the PSTs obtained from the interview about human eye concept
Themes
The suggestions of the PSTs
The PSTs
To associate
“Using from lenses I am trying to detect the eye defect.”
B
“I have myopia and I associate myopia with myself.”
“I do not confuse when I associated with my friends’ the eye defect”G, I
To understand
“In fact, if I find a clue may be permanent”
E
“Latin names must be learned with Turkish means.”
G
“Make coding facilitates learning.”
J
To memorize
“After the interview I'll be gone thoroughly memorized, too embarrassed”
D
“Eye defects should be repeated once a year.”
G
To take care
“I wish I am interest in it at that time I do not forget"
C
The PSTs’ proposals to overcome learning challenges are presented in Table 7. The PSTs offered suggestions such as to associate, understand, memorize and take care in the various themes.
