To answer the slight spoiler question:
***SLIGHT SPOILERS***
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In Thief 3, Garret can zoom and has night vision while zoomed, so that's probably where people got the night vision idea., In Thief 2, he does not have night vision, although he can zoom (default keys are [ to zoom in and ] to zoom out, these can be changed from the options menu). This works a lot like the "bow zoom". Garett also can use a special piece of equipment called the Scouting Orb. This is thrown, much like a flash bomb, and once it lands it interfaces with Garrett's mechanical eye to let him view the surroundings from the Orb's location. So you can throw it around a corner and then take a look, for example. When looking through the Orb, things have a kind of grainy camera look to them, which actually looks kind of similar to the night vision from Thief 3. However, the grainy-ness makes it hard to see much, so in practice it doesn't really give a better view than Garret would normally have. The main advantage is it lets him look from a different vantage point. You can pick the Orb back up after using it too, which is nice.