Let's tackle subtraction first. Subtraction in hexadecimal works similar to subtraction in decimal. Let's do a pair of decimal problems and see if we can parallel the solution method in hex. Suppose we want to subtract 1586 - 243 (in decimal).
Refraction of Light Rays. the bending or deflection of light rays as they pass through the various media of the eye that include the conjuctiva, cornea, aqueous humor, lens, and vitreous body.
When light passes at an angle through a transparent medium, the material causes the photons to change direction slightly. This change in angle is called refraction, and the angle by which the light is bent is determined by the index of refraction of the material.