The scale model eye was developed by scaling an actual cross-sectional picture of an eye from Light & Vision by Mueller & Rudolph. Then a total distance of 2.4 cm from cornea to retina was adopted from Hecht, along with his values for the indices of refraction for all components. The actual measurements for radii of curvature and separation were scaled using a solver program (TK!Solver) until a parallel incoming ray fell on the retina. It is not known whether the eye shown by Mueller&Rudolph is typical.
Thin Film Interference A film of thickness from 0.5 to 10 m is a transparent medium of glass, mica, air enclosed between glass, soap film, etc. When the light is made incident on this thin film partial reflection and partial refraction occur from the top surface of the film. The refracted beam travels in the medium and again suffers partial reflection and partial refraction at the bottom surface of the film. In this way several reflected and refracted rays are produces by a single incident ray. As they moves are superimposed on each other and produces interference pattern. Interference in Parallel Film ( Reflected Rays) Consider a thin film of uniform thickness ‘t’ and refractive index bounded between air. Let us consider monochromatic ray AB is made incident on the film, at B part of ray is reflected (R 1 ) and a part is refracted along BC.At C The beam BC again suffer partial reflection and partial refraction, the reflected beam CD moves again suffer partial