Redshift is an open-source screen color temperature adjustment tool that automatically adjusts the screen’s color temperature based on time to reduce blue light stimulation and better protect eyesight. It works by adjusting the screen's color temperature automatically based on geographic location and time of day, transitioning smoothly between higher color temperatures during the day and warmer tones at night. Redshift can be easily installed on Ubuntu using the command "sudo apt-get install redshift" and can be run either through the command line or a configuration file to customize parameters such as latitude, longitude, and temperature settings. This tool is a valuable resource for eye protection and reducing eye strain caused by blue light exposure.