Human Eye and C...

A person is suffering from myopic defect. He is able to see clear objects placed at $$15\ cm$$. What type and of what focal length of lens he should use to see clearly the objects placed $$60\ cm$$ away 

The hyper-metropia is a 

At sun rise of sunset, the sun looks more red than at mid-day because

Stars are twinkling due to

A person is suffering from 'presbyopia' ( myopia and hyper metropia both defects ) should use 

A person uses a lens of power $$+3\ D$$ to normalise vision. Near point of hypermetropic eye is 

A person wears glasses of power $$-2.5\ D$$. The defect of the eye and the far point of the person without the glasses are respectively 

To remove myopia ( short sightedness ) a lens of power $$0.66\ D$$ is required. The distant point of the eye is approximately 

Colour of the sky is blue due to

The band of seven colours that constitute white light is known as