The defect of vision which cannot be corrected by using spectacles is :

The size of the pupil of the eye is adjusted by :

Who discovered by his experiments with glass prisms that white light consists of seven colours?

The least distance of distinct vision for a young adult with normal vision is about :

The stars appear higher in the sky than they actually are, due to :

A person cannot see the distant objects clearly (though he can see the near by objects clearly).He is suffering from the defect of vision called :

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

Instruments used in astronomical investigations are

We can see the sun before the actual sunrise by about :

A person finds difficulty in seeing nearby objects clearly.His vision can be corrected by using spectacles containing :