Question

Q2. Lenses and the Eye An object O is positioned 3.5 m from a lens of focal length f = -1.5 m as shown:

1. Copy the diagram and draw in:
   1. the path of a parallel ray from the top of the object through the lens;
   2. the path of a ray through the centre of the lens;
   3. and hence the location of the image.
2. Calculate the image distance d_i from the lens. Mark this distance on the diagram in a).
3. A person with myopia wears such lenses to correct for their vision of objects in the distance. The lenses are positioned 18 mm from the eyes.
   1. What is the far point for the eyes?
   2. Find the focal length of the lens inside the eye (f_e) given that the distance between the lens and the retina is 21.1 mm. (Assume that the eye lens can be modelled as a thin convergent lens).

Answer 1