Veins can give you a blue tint. If your eye areas look particularly blue, it could simply be your blood vessels. Blue veins under your eyes look dark, too, so it makes the eyelids and under eyes appear to have dark circles, but really it's just the veins under the skin, explains Dr. Katz.
Thermal imaging is based on heat. All objects, both natural and manmade, emit infrared energy as heat. This energy is actually part of the upper infrared light spectrum. The energy waves can be collected and focused by the right equipment to create a visible image, even when something is not visible to the naked eye.ithin the IR part of the spectrum, there is a long-wave infrared (LWIR) spectrum. There, objects emit energy even when visible light is not present. Thermal imaging... 1  Can highlight people, animals, and objects. 2  Be used to track fugitives or vehicles. 3  Works in both daylight and darkness. 4  Can see through haze and smoke.
What is Infrared? Our eyes are detectors which are designed to detect visible light waves (or visible radiation). Visible light is one of the few types of radiation that can penetrate our atmosphere and be detected on the Earth's surface. There are many forms of light (or radiation) which we cannot see with our eyes.