Question

NEED HELP ON #2

A nearsighted pharmacy student has eyes who have a relaxed refractive power of 49 diopters and her retina is 2.3 cm from her lens.

1). If she is nearsighted, what is her far point? If she is far-sighted, what is her near-point? .1804 m

2) Let's say she wants to be able to focus clearly on objects that are from 150 m to 6.5 cm away. What is the power of the corrective lens she should wear assuming her glasses are 2 cm from her eye? Corrective Power = ___ diopters

Answer 1

F = 49 dioptres x = 2.3 times 10^- 2 m Therefore for at length f = 1/P = 1/49 = 2.04 cm (a) By lens maker formula 1/f = 1/4 + 1/v Therefore 1/v = 1/f - 1/4 1/v = 1/2.04 - 1/2.3 Therefore v = 18.04 cm (b) Therefore do Here v = 18.04 - 2 = 16.04 cm Therefore 1/f = 1/infinity + 1/(- 16.04) Therefore f = - 16.04 cm power p = 1/f = 1/0.1604 Therefore P = - 6.23 dioptres