In the reduced eye model below, all the refraction is assumed to occur at the front surface of the cornea. The refractive index of first medium air is n=1. For this reduced eye model, assume that incident ray travels in a straight line from the object M to point B with incident angle /_a=45^(@). We also know that /_b=7^(@) and /_f=3^(@). After the refraction at the surface of cornea, refracted ray continues in a straight line to the retina. The eye is assumed to be homogeneous. If the image is formed on the retina, what is the second medium refractive index n'? (20 marks)