The script will remind you to take eyes off the screen every hour and keep your eyes healthy.
After you cloned or downloaded the script add it as a cron job.
crontab -e
(a) Remind every hour:
0 * * * * /path/to/eyecare --name yourname
(b) Remind every two hours:
* */2 * * * /path/to/eyecare --name yourname
Or download CronniX for a nice GUI to manage cron tasks under Macos.