As some one who also suffers an astigmatism, the Sig Romeo's are a no-go. Same with it's cousins the Holosun and Primary Arms micro dots.
A couple options:
Eotech - its similar to a red dot, different tech, may or may not work, probably will get worse with age
1x Prism Scope: Vortex makes the Spitfire, kind of large but works great. Leupold prismatic also is out there.
1-4/6x Variable. This is what I run now. Most are very good at 1x, the flexibility to go to 4x or even 6x on some is awesome, adjustable diopter to adjust to your vision. The only real knock on these (since we can't use red dots) is weight. Some can be freaking heavy when a mount is added.
Bushnell Throwdown PCL on the super budget side seems pretty good, Vortex strike eagle might be best bang for buck in optics, Steiner P4Xi in the middle cost spectrum is awesome, Vortex Razor 1-6x on the high end is great. I personally own the Vortex Razor1-6x, and Burris XTR II 1-5x and love them.