Which of the following regulates and controls amount of light entering into the eye?

Where does image formation taking place in the eye?

What is meant by power of accommodation?

When seeing distant objects, focal length of eye must be increased. It is done by

What is the nature of image formed by eye lens?

When seeing nearby objects, focal length of eye must be decreased. It is done by

The minimum distance to which an eye can form clear image of object is called

At the old age the crystalline lens of the eye becomes milky and cloudy. This condition is called

If a person can see distant tree clearly but can’t read books. The person must be suffering from

Curvature of eye lens causes decrease in its focal length that result in eye defect called

If a person can read books clearly but can’t see distant tree. The person must be suffering from

Hypermetropia can be cured by

What is the cause of presbyopia?

In case of myopia the optician prescribe

An old person is not able to see nearby as well as far objects clearly. He went to optician. Which of the following lens the optician must prescribe ?

A prism has two triangular bases and three rectangular lateral surfaces inclined to each other. The angle between the lateral surfaces is called

What is meant by dispersion?

Which of the following color is not observed during dispersion of white light
Blue, Green, Yellow, Violet, Ivory, Orange, Red

Dispersion of light takes place because?

In which of the following case dispersion is likely to occur?

The reason behind flickering is

With respect to atmospheric refraction which of the following point distinguish between cold air and hot air

What is the reason behind twinkling of stars ?

Stars twinkle but planets can’t. Why?

Why sun appears flattened during sunrise and sunset?

What is Tyndall Effect?

Sky appears blue because

During sunrise and sunset, sun appears

If white light is allowed to pass through colloidal solution, the path of light appears to be