6. Exercises VI

1. Why is a normal eye not able to see clearly the objects placed closer than \(25\ cm\)?

 

Our eyes can change the focal lengthangle of incidenceangle of refraction of the lens and hence it can focus on the images from same distancevaried distance. RetinaCiliary musclesCorneaPupil help in changing the focal length of the lens.

 

A normal eye is not able to see the objects placed closer than \(25\ cm\) clearly because the PupilRetinaCorneaCiliary muscles of the eyes are able to contract any limitare unable to contract beyond a certain limit.

 

2. What happens to the image distance in the eye when we increase the distance of an object from the eye?

 

The image distance remains constantdecreasesincreases as the size of the eyes cannot increase or decreaseincreasedecrease.

 

When we increase the distance of an object from the eye, this doesn’t affectaffect the image distance of the eye. This increase in the distance of the object is not compensatedcompensated by maintaining the same focal length of the eye lenschanging the focal length of the eye lens. The focal length of the eyes does not changechanges accordingly to always form an image at the CorneaPupilCiliary musclesRetina of the eye.