RedScreen is a useful utility for night vision.

It serves just one purpose: to preserve your dark adapted eyes, so you can work with your mac in a dark environment.

It does this in two ways:

1. 1.It makes your screen red. Red affects your night vision less than other colours.
   

2. 2.It can darken the screen. It does this by reducing the backlight, and also darkening the colours on screen. It can go VERY dark.
   

RedScreen controls the video hardware directly, so it works with all applications and it restores the system to your original settings as soon as you close the program.

It’s very simple to use. Press the ‘Activate’ button to make your screen red. Control brightness with the ‘Backlight’ and ‘Dimming’ controls. You can turn off the red filter if you just want your screen darker.

There’s a few settings to disable or replace the standard OSX screensaver (if the normal screensaver activates it can briefly disable RedScreen), and an option for greyscale (this can also improve display quality with the red filter active).