# Problem: Light from a distant star is focused by the lens onto the retina . With a pupil diameter of 3.0mm, the intensity of light falling on the retina is illustrated by the graph below . The spot illuminated on the retina is about 8micrometers in diameter. When star gazing on a very dark evening, the pupil diameter will expand to much larger than 3.0 mm.a.With an expanded pupil diameter, what will happen to the total amount of light energy reaching the retina?increase,decrease,or stay the same?b. With an expanded pupil diameter, what will happen to the spread of the image on the retina?increase,decrease,or stay the same?c. With a decreased spread in image size, what will happen to the intensity of the central maxima?increase,decrease,or stay the same?

###### FREE Expert Solution

a.

The amount of light entering the retina increases with an increase in the diameter of the pupil.

This is because the area of light entering the eye is also more.

###### Problem Details

Light from a distant star is focused by the lens onto the retina . With a pupil diameter of 3.0mm, the intensity of light falling on the retina is illustrated by the graph below . The spot illuminated on the retina is about 8micrometers in diameter. When star gazing on a very dark evening, the pupil diameter will expand to much larger than 3.0 mm.

a.With an expanded pupil diameter, what will happen to the total amount of light energy reaching the retina?

increase,decrease,or stay the same?

b. With an expanded pupil diameter, what will happen to the spread of the image on the retina?

increase,decrease,or stay the same?

c. With a decreased spread in image size, what will happen to the intensity of the central maxima?

increase,decrease,or stay the same?