Question

If the object is placed at a distance slightly less than the focal length of a simple microscope lens, what is the nature and location of the closest comfortable viewing distance for the image?

Options

• The image is virtual and closer than infinity, with the closest comfortable distance at the near point

• The image is real and inverted at the near point

• The image is real and the closest comfortable distance is infinity

• The image is virtual and the closest comfortable distance is twice the focal length

Answer 1

When the object is at a distance slightly less than the focal length, the image is virtual and closer than infinity. The closest comfortable distance for viewing this image is at the near point, which is \[D \cong 25\ \text{cm}\]. Viewing at the near point causes some strain on the eye.