Direction of aperture sights?

[PDXGS]

Hi All,
It's been my understanding and experience that the recessed/cupped face of any iron sight aperture should be installed facing the eye to reduce glare.
I've recently purchased a set of Tritium-enhanced XS Sight Systems inserts for an AR and the cupped face on the precision aperture faces away form the eye when the L-shaped flipable insert is installed with the tritium vials correctly facing the eye.
XS claims in their experience that they have better results witht he recess facing away from the eye.
Any comment?

 

[Dfariswheel]

Among others, the M1 Rifle and Carbine had the "cup" facing away from the eye.

This eliminates seeing the edges of the hole if your eye is slightly off-center.

Many target sights do have a "Cup" or even a hood facing the rear as an eye shade.
Depends on the manufacturer and how they "see" things.