Experiment to model the accommodation of the human eye

Abstract We build a simple and inexpensive system that simulates the process of human accommodation. We used a ball lens, made of a male latex condom filled with water, and two diode lasers that can change from collimated to divergent beams, adjusting their rotatory supports. The device is suitable for secondary classes in optics. Students have calculated and measured the focal length of the ball lens (fmeasured /fcalculated = 0.94 ± 0.06) and have studied how human vision shifts from the relaxed condition to the condition of visualizing nearby objects, by squeezing the lens (simulating the crystalline work). Other details of human vision accommodation are also discussed.