Show HN: 20-20-20 rule reminder script for Mac

Hi all, I wrote this script a while back after failing to find a simple way to remind myself to take breaks from my computer screen. Most of the other options out there involve completely locking you out of your screen; I just wanted a gentle notification. I think this has helped me have healthier computer habits and eyes!

If you use Windows or Linux, there's this old thread that might help you do a similar thing: https://news.ycombinator.com/item?id=9406469.