Using a dark background for Vim (background=dark) is eyes-friendly. But in
luminous environments, it makes text quite hard to read, and it requires setting
the background variable to light.
Holy Light is a Vim plugin for MacBook users that sets that setting automatically each time a file or buffer is opened.
Holy Light is Pathogen-friendly.
You simply need to git clone the this repository in your bundle directory, and
reload your Vim configuration (source $MYVIMRC).
The plugin calls the bin/holylight-checker program in order to get the current
ambient light value from the MacBook's sensor.
Depending on the returned value it sets background's value to light or dark.
The binaries' source code can be found here.
If the setting that sets the background to light or dark doesn't suit you, you can easily change it.
Simply run the bin/realtime-checker program, then set the g:holylight_threshold
variable to the value that suits you.
It is named after Stratovarius' Holy Light song.