AGI Well they help with what they call "Irlen syndrome". You can read all about it on their own page: https://irlen.com/what-is-irlen-syndrome/ . There are several posts on LEDSTRAIN about it https://ledstrain.org/d/19-welcome-to-led-strain/47 , https://ledstrain.org/d/188-your-health/175 , https://ledstrain.org/d/81-non-pwm-sufferer-narrowed-down-to-blue-light-sensitivity-or-overuse .
The overlays are just plastic matte elements which can be put on any screen, book, magazine, etc. to reduce or remove the strain due to sensitivity to some color. I found IRLEN syndrome when I searched for fluorescent lighting sensitivity. I have many of the IRLEN symptoms so I thought I might give a try to their overlays. I don't expect that it will do "magic" as these symptoms might be due to many other reasons.
Hisense A2 pro is double screen phone- first screen is normal colored one and the other - EINK. It is much much better than my yotaphone, not laggy, I can answer the phone by not switching sides, the contrast is perfect, the android mirroring function is very good, widget EINK screen has many functionalities. It is a shame that it gives some head tension. But I am going to try adding matte screen protector and later on IRLEN overlays, hope it will help.