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प्रश्न
Write an Explanation.
Power of accommodation
उत्तर
The capacity of the eye lens to change its focal length as per need is called as its power of accommodation.
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संबंधित प्रश्न
List the parts of the human eye that control the amount of light entering into it. Explain how they perform this function.
Write the function of retina in human eye.
Write the function of the following part of the human eye: ciliary muscles
Draw labelled diagrams of the following: Eye
The region of the vertebrate eye, where the optic nerve passes out of the retina, is called the
(a) fovea
(b) iris
(c) blind spot
(d) optic chaisma
Where is the image formed in a human eye?
Name two types of cells in the retina of an eye which respond to light.
What is the principal function of the eye-lens?
What is the least distance of distinct vision for a normal human eye?
Give the scientific names of the following parts of the eye:
carries signals from an eye to the brain.
Fill in the following blank with suitable word:
The part of eye which alters the size of the pupil is............
Explain the functions of the following parts of the eye:
(i) cornea
(ii) iris
(iii) pupil
(iv) ciliary muscles
(v) eye-lens
What is presbyopia? Write two causes of this defect. Name the type of lens which can be used to correct presbyopia.
When is a person said to have developed cataract in his eye? How is the vision of a person having cataract restored?
After testing the eyes of a child, the optician has prescribed the following lenses for his spectacles:
Left eye : + 2.00 D
Right eye : + 2.25 D
The child is suffering from the defect of vision called:
(a) short-sightedness
(b) long-sightedness
(c) cataract
(d) presbyopia
A person got his eyes tested. The optician's prescription for the spectacles reads:
Left eye: − 3.00 D
Right eye: − 3.50 D
The person is having a defect of vision called:
(a) presbyopia
(b) myopia
(c) astigmatism
(d) hypermetropia
Fill in the following blank with suitable word:
Having two eyes enables us to judge.................more accurately.
Five persons A, B, C, D and E have diabetes, leukaemia, asthma, meningitis and hepatitis, respectively.
Which of these persons cannot donate eyes?
Mention if the following statement is true (T) or false (F) Give reason.
Sometimes medicines dropped into the eyes come into the nose and even throat
With reference to the functioning of the eye, answer the question that follow:
Name the cells of the retina and its respective pigments which get activated in the dark.
With reference to the functioning of the eye, answer the question that follow:
Name the cells of the retina and its respective pigments which get activated in the light.
The figure below compares a part of our eye with a part of a photographic camera.
Explain the mode of working and the functions of the parts of the eye mentioned above.
Differentiate between:
Vitreous humour and Aqueous humour.
State the Function:
Cornea
Choose the Odd One Out:
Complete the following sentence with appropriate Word
The photoreceptor cells of the retina sensitive to colour are:
A small hole of changing diameter at the centre of Iris is called _______.
Vision defect that increases distance between the lens of the eye and retina of the eye is termed as myopia.
Given below is a diagram depicting a defect of the human eye. Answer the questions that follow:
- Give the scientific term for the defect.
- Mention one possible reason for the defect.
- What type of lens can be used to correct the defect?
From where the following nerves arise.
Optic nerve
What kind of lens is there in our eyes? Where does it form the image of an object?
______ of the eye is comparable to the film of a camera.
The transparent membrane that keeps the eye moist is ______.
Which one of the following statements is NOT correct?
With neat, labeled diagram describe the structure of retina of eye.
Match the following:
| Column - I | Column - II | ||
| 1 | Retina | a | Path way of light |
| 2 | Pupil | b | Far point comes closer |
| 3 | Ciliary muscles | c | near point moves away |
| 4 | Myopia | d | Screen of the eye |
| 5 | Hypermetropoia | e | Power of accomodation |
Name the following:
Three layers of the eye ball.
Give reason:
Blind spot is considered as 'area of no vision'.
