I had a terrible issue in which every render I did had a glow on the face. I was so frustrated as I looked for hours trying to figure out what the issue was. At first, I believed it was the placement of the lights in which the glare of the rim light was glaring into the lens of the camera. This could not be the case as why would Maya be designed in a way that is years behind camera technology.

I found that the eyeball shader had a glow shader on it. In future, I need to be more aware of what type of special effect I'm adding. In order to improve, I need to learn the function of the shaders and materials. 

From this experience, by discovering these glowing special effects, I was thinking about creating an accessory or weapon which could glow. For example, a lantern or a staff with a glowing crystal.