The following was written for OS 10.8 Mountain Lion but should be applicable for all later versions.
Java software is required in order to run Night Vision, and it is included with most operating systems. However OS 10.8 Mountain Lion doesn't include it, and an upgrade to this OS from a previous version will remove it.
To install Java, launch Terminal from /Applications/Utilities/ and type in:
java -versionand hit return. You'll see a message like: "No Java runtime present, requesting install". Just proceed to install Java.
Under default settings Mountain Lion will refuse to install Night Vision because it is from an "unidentified developer" - the result of new security requirements in place. To fix this the application must be signed, but since I don't have easy access to a Mac development environment it is uncertain if or when this will be done.
As a workaround, the security settings can be changed to allow Night Vision to be installed (and I would recommend changing them back after installation).
This page last updated March 20, 2015