Spell: Heat Sight

Effect

This spell allows the magician the ability to see heat (infrared -- a longer wavelength than the normal rainbow of colors).  

Method(s)

Senses

A magician can gain heat sight by changing the properties of light coming into their eyes to speed it up, decreasing its wavelength. This will allow them to view infrared light in their perceptive range.   More advanced magicians may be capable of speeding up only infrared light, retaining proper color perception otherwise.  

Common Side Effects

This spell may speed up more than just the light wavelengths, causing localized windstorms. It also is likely to cause colors to shift, with the purples shifting out of visible range to ultraviolet, and all color hues being different.  

Might

A magician can gain heat sight by adding additional cones which are capable of seeing infrared.  

Common Side Effects

A common effect is that the colors get compressed when the brain interprets them. Yellow compresses into blue, red into yellow, making room in the perceived color spectrum for "heat" in the red range.   This spell may also cause headaches, sinus pressure, and blurry vision.  

Fortitude

A magician may gain heat sight by changing existing rods to allow them to perceive a different, longer wavelength.  

Common Side Effects

A common side effect will be that the visual range doesn't increase, but rather that it shifts. The shorter wavelengths of light often won't be visible anymore, as the longer wavelengths become visible.  

Relevant Science

An understanding of light and wavelengths makes this spell easier to cast and harder to counter. More understanding of the eye and brain make this spell more difficult to cast, but also make it harder to counter.  

Fundamental Principles

Optics are a fundamental principle for this type of spell.  

Preventative Knowledge

The better understanding of anatomy, specifically as it relates to the eye, make this spell more difficult to cast. For example, once rods and cones are known, the magician would then have to cast the spell by increasing or changing  

Specializations

For specific heat sources, a better understanding of the source can make its heat easier to discern. For example, to use heat sight to detect a specific type of animal, that animal type would need to be well known. The spell may then be able to restrict to just heat sources within a narrower wavelength range.