[Pathfinder] Qustoin about darkvision

[AsheItachi]

So my Aasimar in my game who has 60 ft. darkvision Is asking me if his Darkvision starts at the end of the light spells cast on the other players or is it starting centered on him.
Like for example one character has his shield glowing is out of his range, lets say 70 feet from the Aasimar. So does the darkvision range start on the outer limits of the allied light source.

Or is it just 60 ft darkvision centered on the player no matter what other light sources are around.

[Arkain]

"Darkvision is the extraordinary ability to see with no light source at all, out to a range specified for the creature. Darkvision is black-and-white only (colors cannot be discerned). It does not allow characters to see anything that they could not see otherwise—invisible objects are still invisible, and illusions are still visible as what they seem to be. Likewise, darkvision subjects a creature to gaze attacks normally. The presence of light does not spoil darkvision."

In other words, yes, you have a given range, "centered on the player" to use your words, within which you can see with darkvision. Or at least that's how I've always understood it to work. If you have light, you may use it to discern colors and such as normal, but when it's not advantegous, for instance because the light does not extend the entire range of your darkvision, your darkvision can take care of the rest just fine.