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प्रश्न
In a relaxed state, the focal length of healthy eyes is _______.
पर्याय
2 cm
2.5 cm
25 cm
5 cm
उत्तर
In a relaxed state, the focal length of healthy eyes is 2 cm.
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संबंधित प्रश्न
Write the function of the following part of the human eye: crystalline lens
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
The size of the pupil becomes ______ when you see in dim light.
Explain the mechanism of vision.
Match the following:
| Column I | Column II |
| (i) Myopia | (a) Converging power of eye lens becomes low |
| (ii) Hypermetropia | (b) Converging power of eye lens remains the same |
| (c) Converging power of eye lens becomes high |
A person got his eyes tested by an optician. The prescription for the spectacle lenses to be made reads :
Left eye : +2.50 D
Right eye : +2.00 D
State whether these spectacle lenses will converge light rays or diverge light rays.
Out of rods and cones m the retina of your eye:
which work in dim light?
What is the range of vision of 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 words:
When light is dim, the pupil becomes................
How is the amount of light entering the eye controlled?
Why does it take some time to see objects in a dim room when you enter the room from bright sunshine outside?
If you walk from a dark room into sunlight and back again into dark room, how would your pupils alter in size? What makes this happen?
How much is our field of view:
with one eye open?
With both eyes open, a person's field of view is about:
(a) 90°
(b) 150°
(c) 180°
(d) 360°
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
Mention if the following statement is true (T) or false (F) Give reason.
Short-sightedness and hyperopia are one and the same thing
Given below is a set of five parts. Rewrite them in correct sequence.
Conjunctiva, retina, cornea, optic nerve, lens.
Give scientific reason:
We cannot clearly see an object kept at a distance less than 25 cm from the eye.
Define the following:
Yellow spot
Give the main function of the following:
Lachrymal glands
Choose the correct answer.
Which one is the photoreceptor _____________
What happens to the image distance in the normal human eye when we decrease the distance of an object, say 10 m to 1 m? Justify your answer.
What is meant by power of accommodation of the eye?
What is a stereoscopic vision?
State the Location of:
Lacrimal gland
State the Function:
Iris
Draw a scientifically correct labelled diagram of a human eye and answer the questions based on it:
- Name the type of lens in the human eye.
- Name the screen at which the maximum amount of incident light is refracted?
- State the nature of the image formed of the object on the screen inside the eye.
Write the name.
The fleshy screen behind cornea.
Complete the paragraph by choosing the right options given below.
(minimum, near point, 25 cm, farthest, farthest distance, far point)
The _______ distance of an object from a normal eye, at which it is clearly visible without stress on the eye, is called the minimum distance of distinct vision. The position of the object at this distance is called the _______ of the eye, for a normal human eye, the near point is at _______. The _______ distance of an object from a human eye, at which it is clearly visible without stress on the eye is called _______ of distinct vision. The position of the object at this distance is called the _______ of the eye.
Draw the struture of human eye and label its parts.
In the figure of the human eye, the cornea is represented by the letter
Name the part of the eye which gives colour to the eyes.
The coloured portion of the eye is the ______.
Which cells of the retina enable us to see coloured objects around us?
With reference to human eye, answer the following question.
What is blind spot?
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 |
Where is the following located?
Yellow spot
