Please, Show work. A myopic eye has its far point at 50 cm. This myopia is due t
ID: 1427258 • Letter: P
Question
Please, Show work.
A myopic eye has its far point at 50 cm. This myopia is due to the deformation of the eye ball, and the focusing system of the eye is normal, with the focal length of 2.290 cm for a relaxed eye, and f = 2.098 cm for an eye accommodated to a near point (assuming the "reduced eye" model). A) What is the power (in diopters) of the corrective lens that is needed for clear vision of distant objects (neglect the separation between the eye and the corrective lens)? B) What is the near point of the eye?Explanation / Answer
A) 1/v -1/u = 1/f
for normal eye, u = far point = infinity
1/v = 1/f where f is normal focal length
for myopic eye,
1/v + 1/0.50 = 1/f ' where f ' is myopic focal length
=1/0.0229 =43.668
1/v = 43.668 -2 = 41.668
normal power = 1/f = 41.668, power of myopic eye =43.668
power of lens required = 41.668 - 43.668 = -2 Diopters
B)1/v - 1/u = 1/f ''
41.668 - 1/u = 1/0.02098 =47.664
1/u = 41.668- 47.664 = -5.996
u = - 0.1668 m = -16.68cm
Hence near point is -16.68cm