Extra Credit My right eyes near point is 5 cm and farpoint i

Extra Credit: My right eye\'s near point is 5 cm and farpoint is 11cm. What power contact lens should I use to see faraway objects with a relaxed eye. What is the nearpoint of my left eye while wearing the contact lens of part A)?

Solution

Part A.) The farpoint of the eye has come down to 11 cm, however, we wish to see the far away objects \'normally\' the image must form at the farpoint of the eye.

So, we can write: 1/do + 1/di = 1/F

Here 1/do = 0

So, -1/11 = 1/F

Therefore the required power would be: -0.091 The negative sign shows the lens to be used is concave.

Part B.) For the nearpoint again, we can write:

1/do - 1/5 = -1/11

or, 1/do = 1/5 - 1/11

or, do = 9.167 cm

Therefore the near point changes to 9.167 cm