The Daraz are primarily a subterranean species, and have poor eyesight as a result. They rely more on sonar for navigation (hence those big ears), but what they do see is in the infrared spectrum.
The dots just below the Daraz’s eyes are pit organs, which sense infrared light as heat (similar to how a pit viper detects warm objects). The heat information gleaned from the pit organs is ultimately processed by the same part of the brain as the eyes (again, similar to pit vipers).
A heat imprint can last for several minutes. If, say, a person was sitting in a chair but got up and left the room, the body heat they imparted to the chair would still be visible in infrared until the chair returns to room temperature.
While infrared vision registers heat, infrared is actually a wavelength of light, and it behaves differently from visible light in several notable respects: water and glass both appear opaque in infrared, and extremely smooth surfaces can have a mirror-like reflection, even if they’re made of wood or stone.
Because sight is considered a lesser sense by the Daraz, their idioms reflect their preference for hearing and smell. So, while a human might say, “I see what you mean,” the Daraz would instead say, “I hear you on that,” or “I catch the scent of it.”