Raspberry Pi is a great tool for teaching. Its affordable price makes it appealing for students and teachers that can make interesting “experiments” without spending a fortune.
The understanding of optics requires lot of geometry, but equations are deeply understood only by a small number of students. Drawings may help, but making them requires some ability and precision. Needless to say, in most cases, the result is static and, in order to understand what happens in different conditions, require to realise many drawings.
A very interesting alternative is using an application called GeoGebra that can be downloaded for free from the Internet. Interesting enough, GeoGebra runs on Raspberry Pi. Every student, then, can do his/her own experiment with optics using GeoGebra. See this post to learn how to install it (quite simple, in fact; the only tricky part being installing the Java virtual machine). In short, download the arm version of the Java VM fromhttp://jdk8.java.net/fxarmpreview/index.html, then issue the following commands in a terminal