Answer to Question #287050 in Optics for Elle

Question

A small alien species with many tiny eyes is discovered. After analysis, we learn that light is focused on their transparent retina after being reflected off a concave mirror located at the back of their eyes. Assuming the eyes of this species only consist of a concave mirror with a radius of curvature of 420 µm immersed in a medium with a refractive index of 1.492:

 

a) Calculate the refractive power of the alien eye. (2 marks)

Answer 1

$D=\frac nF=\frac{2n}R=7100~dpt.$