What is presbyopia? Write two causes of this defect?

What is hypermetropia? What are the two causes of this defect of vision?

How can this defect of the eye be corrected? Illustrate your answer by drawing ray diagram to show the formation of image by a hypermetropic eye?

A beam of white light falling on a glass prism gets split up into seven colours marked $\mathit{1}$ to $\mathit{7}$ as shown in the diagram. A student makes the following statements about the spectrum observed on the screen:

The colours at positions marked $\mathit{3}$ and $\mathit{5}$ are similar to the colour of the sky and the core of a hard-boiled egg respectively.
Is the above statement made by the student correct or incorrect? Justify.

A beam of white light falling on a glass prism gets split up into seven colours marked $\mathit{1}$ to $\mathit{7}$ as shown m the diagram.

Which two positions correspond closely to the colour of:  A solution of potassium permanganate? Danger or stop signal lights?