Factory adjustable iron sights.
Through the efforts of many greats, decades ago, the bugs have been long worked out. Whether it be the work of makers like King or Micro, or guys who lived in the field, like Doug Wesson, Keith, McGivern, they figured it out long ago. Square notch, U notch, V notch, peep sights, etc....It's all been done in the last century.
I'd sooner trust them than some tacticool wannabe trying to make a fast buck reinventing the wheel.
But, I've been told I'm getting to be a curmudgeon set in my ways.
So, take it with splash of hot sauce.
But, if your eyes need some help, the world of optics might be in your future.
Best Regards,
Jim