Use a Fresnel Lense and some wood to create a frame to hold the lens.
https://www.amazon.com.au/s?k=fresnel+lens
I have the same issue. I can't wear contacts, they make me dizzy, and I don't want to wear glasses on stage. I've done that. I actually took two of the plastic fresnel lenses and cut them out.(from the middle section) and put them back to back (taped them together with a thin strip of tape) a little larger than the screen. then I cut two small pieces of wood(painted them black) about an inch high one side a little lower, like a ramp. Put velcro on the wood, the remote, and both sides of fresnel lense, left and right. I can take it on and off.I keep the lense in a plastic bag as they get scratched easier. it works. Not great but it's better. I only use performance mode and I use each button 1,2,3,4,5 as different songs and I have been begging them to make a "Layout D" so the rig names(songs for me) are in a very large font like in "Layout C" which make the Performance names huge. It would solve the one and only one problem I have with the Kemper.