The cornea behaves as a thin lens of focal length approximately 1.8 cm,
although this varies a bit. The material of which it is made has an index of
refraction of 1.38, and its front surface is convex, with a radius of
curvature of 5.0 mm. (a) If this focal length is in air, what is the radius of
curvature of the back side of the cornea? (b) The closest distance at which a
typical person can focus on an object (called the near point) is about 25 cm,
although this varies considerably with age. Where would the cornea focus the
image of an 8.0-mm-tall object at the near point? (c) What is the height of
the image in part (b)? Is this image real or virtual? Is it erect or inverted?
(\(Note:\) The results obtained here are not strictly accurate because, on one
side, the cornea has a fluid with a refractive index
different from that of air.)