[Interesting but not a very difficult task to be attempted]
Objects Required:- an empty glass,a glass filled with water and a piece of paper with an arrow drawn it.
STEP 1. Take the empty glass and place the piece of paper with an arrow on it behind the glass
Observation:- No change will be seen.
STEP 2. Now,take the glass filled with water and place the piece of paper with an arrow behind it.
Observation:- Direction of the arrow chnages.
Reason:-The light is refracted as it passes through the transparent glass,the water,then through the back of the transparent glass and finally through the air to the paper with horizontal arrow. This refraction causes the horizontal arrow to appear as if it is reversed.