It's a good idea to purchase the night vision goggles as soon as they become available. They allow the thief to see in low light conditions without the danger of creating a light that could attract attention, like the flashlight.
Because there are several houses with dark furniture, the night vision goggles can be especially handy when searching for every last lootable item. Unfortunately, it becomes very difficult to see out of them during the daylight hours.
Note: The flashlight and night vision goggles are activated with different keys/buttons; therefore, a player can continue to use both if they choose.