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प्रश्न
Define the following term:
Adaptation
उत्तर
There are two types of human eye adaptation.
- Light adaptation: When a person with dark-adapted eyes moves to a brightly lit area, as in coming out of a cinema hall after the noon show, he experiences a dazzling effect for a short period. After a few seconds, he comes back to normal viewing through light adaptation.
- Dark adaptation: When you pass from a brightly lit area to a dark room (such as a cinema hall), you experience difficulty seeing objects for a short while. Slowly, your vision has improved. This improvement is called a dark adaptation.
संबंधित प्रश्न
The least distance of distinct vision for a young adult with normal vision is about ______.
Why is a normal eye not able to see clearly the objects placed closer than 25 cm?
What happens to the image distance in the eye when we increase the distance of an object from the eye?
The change in focal length of an eye lens is caused by the action of the ______.
Write the name.
The sensation on the retina persists for a while is
Write the name.
The persons which are unable to distinguish between different colours
Identify and explain concepts given in this diagram.
The eyes of the nocturnal birds like owls are having a large cornea and a large pupil. How does it help them?
Having two eyes facilitates in
A: Increasing the field of view
B: Bringing three-dimensional view
C: Developing the concept of distance/size
Then the correct option is/are
Near and far points of a young person normal eye respectively are:
The ability of the eye lens to adjust its focal length to form a sharp image of the object at varying distances on the retina is called:
A student sitting on the last bench can read the letters written on the blackboard but is not able to read/the letters written in his textbook. Which of the following statements is correct?
When light rays enter the eye, most of the refraction occurs at the
In simple microscope ______ lens is used.
Adjusting the focal length of the eye lens to view objects at different distances is done by ______.
Give the reason for the following:
A person from bright sunlight outside enters a poorly lit room and feels blinded for a short while.
The figures (A) and (B) given below are showing some kind of adjustment. Study the figures and answer the questions that follow.
| A |  |
 |
B |
- Identify the kinds of adjustments done in the figures (A) and (B).
- Distinguish between the adjustments of figures (A) and (B) on the basis of:
- The size of pupil.
- The pigment which gets regenerated.
- Cells of the retina.
