Q5. a) Calculate the position of the six cardinal points (focal points, principal points, and nodal points) in the human cornea. Assume the cornea is a thick lens separating air (n = 1) and aqueous humour (n = 1.336). The refractive powers of the first and second surfaces are +47.898 D and -5.952 D, respectively. The cornea is 565 um thick and has a refractive index of 1.376. Draw a diagram showing where all the cardinal points are located. (8 marks) b) The figure below shows a thick lens with the positions of the principal planes, principal points and distances between vertices and principal points (6 and o'). State if the positions of both principal points could be correct or if they could never be in that position. Explain why (use any equations necessary to do so). (2 marks) P P' 8' = 0