You can change the width,LEFT curvature,RIGHT curvature of the lens.
Index of refraction for the lens and the surrounding environment can be adjusted.
Try and play with it!
1. circular glass 2.parallel light through water drop 3.glass Lens A 4.glass Lens B 5.glass Lens C 6.glass Lens DVirtual Physics laboratory Original URL
Fu-Kwun Hwang, Dept. Of Physics, National Taiwan Normal University.