Question

A typical human lens has an index of refraction of 1.430. The lens has a double convex shape, but its curvature can be varied by the ciliary muscles acting around its rim. At minimum power, the radius of the front of the lens is 10.0 mm, whereas that of the back is 6.00 mm. At maximum power, the radii are 6.50 mm and 5.50 mm, respectively. If the lens were in air, what would be the maximum power and associated focal length of the lens? maximum power: diopters focal length: m What would be the minimum power and associated focal length of the lens? minimum power: diopters focal length: m

Answer 1

n 1.430 10 mm Inden of refraction Radius of front lens ri Radius of back len ra Manemum power radii are 6 mm 6.50 mm and 5.50 mm. a. Maximum power. 8 = 6.50 mm & ra a 5.50 rom. P= :(n-1)(***) 3 - (1.430-1) 3 10 6.50 + lo 5.5 Pmaxe = 144. 3357 D 3 froon -- - m 16.93x10 Prane 144.3357 b. Minimum Power. 3 103 Þ: (1.430-1) Go + f | Pomin 114.667 D forsin 2 8.72x103 Porosis c. U= 29.5 cm fmore 6.93 mm 0:693 cm. 12 I f - I २१.5 0.693 2 v=o. 7097 cm ve 0.7097x10