Human lag is a reality. Our response doesn’t affect the physics, so far as I know, although it may affect our explanations of nowness.
I don’t think we have that speed. Photons slow down in the atmosphere, even moreso when they hit the outside layer of the eyeball, slow further going through the fluid, until they reach the little sensors in the back middle of our eyeballs.
There the photons bleach various photonic cells temporarily (chemical reaction) and the bleaching is converted to electric signals that go down the optic nerve, while the cells quickly recover from their bleaching.
What we experience is a photon’s final destination. We are where the photons we use, stop.