The beam form of heat vision is far more precise, accurate and powerful, with the thick beams being intense enough to easily burn and cut through the most durable of metals (even extremely durable Kryptonian alloys), and while they cannot harm a Kryptonian, it does cause them immense burning pain on impact. The ability seems to originate from the nerves inside the face in the parts closest to the eye, or from the nerves connected the brain to the eye. The energy inside the face seems to cause a distortion of pressure in the face, as the veins near the eyes protrude and stretch out the faced when heat vision is being used or focused. When in use, the energy used in heat vision builds in the nerves around the eyes and is focused and concentrated inside the eyes. This causes the veins and nerves in the faces to produce an intense orange glow and the eyes to shine with the same light, with the only difference being that the light from the eyes is far brighter. When the beam is used, all the energy is instantly diverted to the eyes and blasted out.
When angry, or to make a threat, Kryptonians may cause their eyes to glow a threatening red, without any strong beams actually emerging from their eyes.