I do almost everything on a monitor. I don't have a backlit keyboard, yet.
I was trying to figure out what an appropriate lighting kevel was. I found there are now apps to use your cell-phone as a light meter.
IES doesn't call out a level for strictly using a computer screen 8 hours a day or more.
I think 30 foot candles is too much. That, and on a personal level, my eyes are old. They don't adjust the way they used to.
https://www.resourceltg.com/wp-content/uploads/2019/10/Interpretation-of-IES-Standards-Resource-1.pdf
https://www.resourceltg.com/ies-footcandle-guide/
https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://waypointlighting.com/uploads/2/6/8/4/26847904/ies_recommended_light_levels.pdf&ved=2ahUKEwiIk8GNv_ODAxWiLDQIHR_wDl0QFnoECCUQAQ&usg=AOvVaw2KhvnSA4zjKiy0O1hqtFiy