A Nearsighted Person Cannot See Objects Clearly Beyond 25.0 Cm (her Far Point). If She Has No Astigmatism And?
December 3, 2009 by admin
Filed under FAQ on advance for astigmatism
contact lenses are prescribed for her, what power of lens is required to correct vision? Give your answer in diopters with one decimal point accuracy. Hint: Lens power P = 1/f , where lens focal length f is measured in meters. In this case units of power is a diopter.
She needs a diverging lens to change her far point from 0.25 m to infinity.
1/f(corr. lens) + 1/d(uncorr) = 1/d(corr) = 1/infinity = 0
f(corr. lens) = -d(uncorr) = -0.25 m
P = 1/f(corr. lens) = -4.0 diopters.
6 diopetorsactions