We've seen how he interprets people and things with his VISOR, but if the holodeck is all force-fields and holographic imaging, how does he interact in a similar way to other members?
What does the holodeck look like to Geordi LaForge using his VISOR?
Taking the novelisation for TNG: Descent into account, it would seem that Geordi isn't fooled by the holodeck one bit. He can choose to see the spectrum that will allow him to perceive them, but at the same time he also sees that they have neither true form nor true substance, describing the place as little better than a cartoon.
Geordi saw through the images as he did all holodeck images. No heartbeats, no heat generation, no pulse. The fabulous science here tried very hard to make these beings appear real, but Geordi, the Enterprise’s one blind crewman, could see right through them by using another science.
The holodeck should have been just that to him—hollow. Nothing here should ever have succeeded in fooling him, drawing him into the scenario.
But that had happened before. He’d come into this place where everything looked like a cartoon, and he’d allowed himself to be caught up in the people he met and the things he “saw.”
That’s how I know I’m more human than machine, he realized as he stared at the three people around the table, and as he sank tentatively into the dealer’s empty seat.
Let me attempt an answer using only canon (TV and movies) content.
Justification:
In "I, Borg", we have this exchange regarding Hugh:
CRUSHER: That's right. He's gotten every one. Eight out of eight. That blows the top right off the spatial-acuity percentiles.
LAFORGE: It's the prosthetic eye. It seems to be giving him very complex visual information.
CRUSHER: Like some kind of holographic imaging system.
LAFORGE: That could be helpful. Hugh, I'd like to take a closer look at your eyepiece. Is that okay?
In other words, Borg ocular prosthetics are technologically remarkable, even to LaForge, who knows a lot about ocular prosthetics (and a lot about a lot).
Yet, in Star Trek: First Contact, it is shown that Borg can be fooled by the holodeck when Picard and Lilly hide in the "Dixon Hill" simulation.
Hence, we can conclude that if LaForge can distinguish a holodeck simulation from reality, it must be due to differing abilities of his vs. Borg prosthetics. And given LaForge's comments, it appears it can't be due to basic perceptual ability like resolving capability, since that is apparently better or equal for Borg compared to himself.
It could be that the holodeck can also generate information that syncs up with Geordi's visor, so that whatever happens there might appear realistic to him.
In fact, as he's essentially wearing a VR headset, that would be easier to do than it would be for people using fully functional eyes.
I assume Geordi isn't the only blind person using a visor, so this would be a valid feature to include.
