I too, for a time, had setup my system so that windows were partially transparent. It looked cool, and helped to find windows when they were hidden behind other ones. Then, one day, I turned the partial transparency off, and found it to be very relaxing on my sight and brain. I didn't feel any strain when I started, but I guess it accumulated.
For context, I use a tiling window manager with an average of 4 to 7 windows per workspace-monitor combo. Back then, I also set up a moving background (a screensaver always on in the root window). In fact, I think that was the primary motivator. I had gone years without a wallpaper because having a tiling window manager made it meaningless and I was missing having some eye candy. Having partial transparency would let me see the moving background through the windows. Anyway, I digress and I'm back to no transparency, no background, in any case.
For context, I use a tiling window manager with an average of 4 to 7 windows per workspace-monitor combo. Back then, I also set up a moving background (a screensaver always on in the root window). In fact, I think that was the primary motivator. I had gone years without a wallpaper because having a tiling window manager made it meaningless and I was missing having some eye candy. Having partial transparency would let me see the moving background through the windows. Anyway, I digress and I'm back to no transparency, no background, in any case.