"Eyes and Glasses" Lenses and Their Applications PPT Courseware

Description

"Eyes and Glasses" Lenses and Their Applications PPT Courseware

1. The structure of the eyeball:

ciliary body cornea lens

Vitreous Retina Optic Nerve

2. How do human eyes see objects?

The imaging principle is the same

Comparison, what did you find?

The process of seeing things with the human eye

camera imaging process

3． Myopia and its correction

Cause: The lens is too thick or the eyeball is too long in the front-to-back direction.

Image location of distant objects Preretinal

corrective concave lens

Self-learning:

Read the content of "The World of Science" on page 98 of the textbook and answer the related questions at the end of the reading material.

discuss:

Analysis based on the structure and imaging principle of the eye: In order to protect our vision, what eye hygiene should we pay attention to, and why?

5. Eye hygiene

Teenagers who use unhygienic eyes can easily develop myopia. So, how do we prevent myopia?

1. Clear vision distance

Through the adjustment of the lens, the eye can make objects of different distances form clear images on the retina. The two extreme points of eye adjustment are called the far point and the near point. The far point of a normal eye is at infinity, and the near point is about 20cm. The distance at which normal eyes can observe nearby objects most clearly without fatigue is about 25cm, which is called the photopic distance. Read the words in the book, measure your photopic distance, and compare it with other students: Is the photopic distance the same for normal eyes and myopic eyes? What are the rules?

1. The clear vision distance of myopic eyes is shorter than that of normal eyes;

2. The photopic distance of different myopic eyes is also different;

3. The photopic distance of the hyperopic eye is longer than that of the normal eye.

Feedback exercise:

1. Regarding myopia and its correction, which of the following statements is correct ( )

A． Myopia can only see close objects clearly, but cannot see distant objects clearly

B. The cause of myopia is that the lens is too thick or the eyeball is too long in the front-to-back direction.

C. Light from a certain point in a distant object reaches the retina of the myopic eye before it converges.

D. Myopia is corrected by placing a convex lens in front of the eye

2. Regarding hyperopia and its correction, which of the following statements is correct ( )

A． Hyperopia can only see close objects clearly but not distant objects

B. The cause of hyperopia is that the lens is too thin or the eyeball is too short in the front-to-back direction.

C. Light from a certain point in a nearby object has not yet converged and has reached the retina of the hyperopic eye.

D. Hyperopia is corrected by placing a convex lens in front of the eye

3． Grandpa Longlong’s eyes are presbyopic, and his father is short-sighted. Both men's glasses are placed on the newspaper on the desk, as shown in the picture. Now grandpa wants to read an instruction manual. Longlong should give grandpa the glasses on the ______ side of the newspaper. (fill in: "left" or "right")

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For more information about the PPT courseware "Lens and Its Applications in Eyes and Glasses", please click the "Lens and Its Applications ppt Eyes and Glasses ppt" tag.

"Eyes and Glasses" Lenses and Their Applications PPT Courseware 8:

"Eyes and Glasses" Lenses and Their Applications PPT Courseware 8 Learning Objectives 1. What are the main parts of the human eye? 2. How do human eyes see objects? 3. How does the human eye see objects at different distances? 4. What indicates the refractive power of a lens? 5. The formation of myopia..

"Eyes and Glasses" Lenses and Their Applications PPT Courseware 7:

"Eyes and Glasses" Lenses and Their Applications PPT Courseware 7 Think about what you know about your eyes. How do the eyes see these objects? 1. Eyes 1. Structure of the eyeball (1) Lens and cornea: the combined effect is equivalent to A convex lens (2) retina: quite...

"Eyes and Glasses" Lenses and Their Applications PPT Courseware 6:

"Eye and Glasses" Lens and Its Application PPT Courseware 6 Learning Objectives: 1. Understand the structure of the eyeball and how the eye sees objects clearly. 2. Understand the causes of myopia and hyperopia, and know how to correct myopia and hyperopia. 3. Understand the common sense of eye protection. ..

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Update Time: 2024-11-22

This template belongs to Physics courseware People's Education Edition Physics for Grade 8, Volume 1 industry PPT template

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