This doesn’t make sense to me. The iris doesn’t collect light for vision. The pupil expands or contracts to vary the amount of light that reaches the retina. Iris color should have nothing to do with it.
From the first source on the linked study, they describe it as the following:
(…) This functions as a mirror providing the second opportunity for photon capture by reflecting light back through the retina, enhancing visual sensitivity.
This doesn’t make sense to me. The iris doesn’t collect light for vision. The pupil expands or contracts to vary the amount of light that reaches the retina. Iris color should have nothing to do with it.
From the first source on the linked study, they describe it as the following:
But the iris is a mask, it blocks off axis light