For viewing near the normal direction, it can be shown
that the apparent depth (h1) is real depth (h 2) divided by the refractive
index of the medium (water) 9 4  TOTAL INTERNAL REFLECTION
When light travels from an optically denser medium to a rarer medium
at the interface, it is partly reflected back into the same medium and
partly refracted to the second medium This reflection is called the internal
reflection