Are you spending time in modern artificial lighting and behind a computer, tablet, or cellphone screens after sundown?
The orange Rhythm500 lens blocks out 100% of blue light and filters out roughly half of the green light spectrum. It retains high transparency making them very useable and a great introduction to blocking blue light at night.
The red Rhythm560 lens goes further to block almost all green light, right up to 99.64% at 560nm in fact. Developed for the hardcore biohacker seeking maximum melatonin preservation.