AirNGasman, thank you for posting that book excerpt. The effects of light intensity and angle are of great interest to me, since I prefer open sights but have both astigmatism and cataracts, and they behave differently on different days.
The pistol sights (a PB with standard blade front and notch rear, and a P3 with fiber optic sights) are the hardest to deal with, but the air rifles also can be troublesome. One has post and notch, another one has post and rear peep, and another is presently scoped but has been shot more using the standard open sights than with the scope. The peep sight has been easier to use than either of the other nonmagnified aids.
One thing I tried, space and conditions permitting, was to move myself to a different angle relative to the sun and the target. This has helped a lot, and the comment in the quoted text about the policeman's experience totally fits.
Regarding pest shooting with open sights, I agree. Pest removal has just become more important here, and shooting with the peep sighted gun was faster and simpler than using the scoped rifle.