These files describe an eyepiece which can be used for a DIY camera lucida. There are two components: (1) the main body of the eyepiece, in which is mounted a 5x5x10mm mirrored right prism, and (2) an endcap which keeps the prism in place. The eyepiece body comes in left-handed and right-handed versions. For more information, please see http://neolucida/diy.
For information about how to print and assemble this eyepiece, please see http://neolucida.com/diy/. These files were designed by Zack Jacobson-Weaver for NeoLucida project, directed by Pablo Garcia and Golan Levin.