How can iPhone SE 2022 vs Second Generation feel less eye strain?

i find less eye strain from iPhone SE2022 than Second Generation. How can that be possible when both has same Display specifications. My comparison is done with Accessibility turned on for Reduce Transparency, Increase Contrast, Differentiate Without Colour, Smart Invert, Colour Filters, Reduce White Point, Auto-Brightness. The SE2022 seems much easier on my eyes. What can explain the difference when both share same display specs?