OK, I just went out and actually paid attention...
At 5'10", I find eye level to be about 1/3 up from the bottom of the window if I'm sitting with a straight back.
If I'm leaned over the table reading or some such, then I'd be happier with a slightly higher seat.
If I'm leaning against the bathroom wall with my feet up on the bench, then eye level is about at the bottom of the window.
So, a reasonable height first thing in the morning, but as the day wears me down I need to lower the windows
I'll see what the wife thinks of the idea, but I may put adding a 3" riser to the benches on my project list. The bench might be too tall for her in that case, though. Raising the floor as well as the bench would work, but then it's be a tripping hazard.