I know that Geordi's blind, but with his VISOR, he has exceptional vision with a range for a wide subspace spectrum. How does this compare with Data's android vision: Does Data have a comparable vision of the spectrum to Geordi, or is he limited to standard visible light like humans?
Think this really depends on what you're "looking for" (pun intended).
There are examples where Geordi has the clear advantage (as mentioned by Richard: Generations being one example with the hidden door).
However, it's never really explained how Data sees things (as far as you could consider his perception seeing).
Geordi's vision is clearly augmented and he's unable to see "normally" (at least if you skip the latest movie adaptions, where he's got in-eye implants).
In Data's case I'd assume his vision is artificially limited (unless specifically modified for plot reasons), simply to make him more human.
So if you're looking for things invisible to the human eye, I'd guess Geordi has the advantage.
If you're talking about normal things perceivable by the human eye, Data seems to have the advantage (at least when considering "Visor Geordi").
Geordi's vision is better
Per Compro01's comment about "Encounter at Farpoint", Data himself indicates that he considers his own visual abilities to be inferior to that afforded by Geordi's Visor (which can apparently register electromagnetic signals across the entire EM spectrum between 1 Hz and 100,000 THz)
It would seem that Riker also concurs.
And in the original script for Star Trek : First Contact we learn that although Data's vision is noticeably better than a normal human's (and that he can also see beyond the ultra-violet and infra-red) this certainly doesn't compare with Geordi's range.
I have some experience working with industrial assembly line cameras; those cameras can make amazing calculations on very little visible data. Similarly, I think that Data's better-than-human vision does not come from better recording equipment (eyes), but better processing.
The human brain is adept at picking out patterns and differences; when Geordi found the hidden door (as mentioned by Richard), his human brain was able to quickly isolate and process the relevant visual information. Data, on the other hand, has an advanced information processor; just like industrial cameras, Data may not be great at spotting tiny details on the first pass, but he can add post-processing filters and do side-by-side comparisons that no human could ever handle. That is how he can accurately measure distances or sizes with only his eyes; he could measure a heartbeat by comparing the difference in pixels between frames in a heavily post-processed video of someone's wrist.
Thus, I believe that while Geordi may have a much wider vision spectrum, Data would easily be the fastest at a "spot the differences" puzzle.
While it isn't necessarily a canonical source, the ST:TNG video game for the SNES, Genesis, and Game Gear provides an idea of how well Geordi and Data see in the dark. In the game, Geordi sees better than Data in the dark, and both of them see better than the other crew members - which sounds like it meshes pretty well with what others have mentioned from the series.