When a photon is absorbed, it raises the electromagnetic potential, usually of an atom or molecule’s electron orbit. Then if it is the right kind of molecule and substance (photosensitive), that higher potential releases a small electric pulse as an electron breaks free. In the case of an eye, it is a bioelectric pulse that gets into the scheme of your brain.
Of course when you calculate momentum with frequency, you end up with an interesting result due to red/blue shifting. The momentum of the photon changes merely because You were moving. Yet the speed of light is “always observed as the same”. So moving toward a light source, the light comes at you at the same speed, yet hits you harder, more momentum/energy. Yet you can’t know that you are moving… another of those paradoxical situations proposed by Special Relativity. I get a kick out of these theories that propose that something far away changes Its properties because of something You are doing. They seem so self centered and arrogant. “Watch Me. I can change the momentum of that photon and the star it came from with my bare feet.”