Human Eye and C...

An old person is able to see an object nearest to 1 m.What should be the power of lens required so that he can see an object placed at nearest distance of distinct vision?

In the figure below for no dispersion to take place, light rays must enter from _____ and emerge from _____.

A person cannot see distant objects clearly. his vision can be corrected by using the spectacle containing :

Rainbow is observed when the Sun is 

A person can see clearly objects only when they lie between $$50$$cm and $$400$$cm from his eyes. In order to increase the maximum distance of distinct vision to infinity, the type and power of the correcting lens, the person has to use, will be?

A young man has to hold a book at arm's length to be able to read it clearly. The defect of vision is: 

Though a woman can see the distant objects clearly, she cannot see the nearby object clearly. She is suffering from the defect called :

What is the common phenomena of light between random wavering of flickering of objects seen through a turbulent stream of hot air, advance sunrise and delayed sunset and twinkling of stars?

A person can not see the distant objects clearly (though he can see the nearby object clearly). He is suffering from the defect of vision called:

The near point and the far point of a child are at 10 and 100 cm. If the retina is 2.0 cm behind the eyelens  .What is the range of the power of the eye lens?