Why does the immediate area around a fire appear darker, once the flames really get going?


Ever look at a fire that is going during broad daylight? It seems to eventually suck the brightness out of the surrounding area. You may or may not have experienced this, personally, but I know that it definitely happens.

You would figure that the opposite of this phenomena would happen, but it doesn’t.

When I was young and went to church, I remember looking at the candles and after a few minutes of uninterrupted staring, the area would become darker (the wait time doesn’t seem necessary for big fires, though).

I looked into it a little bit, but I have no answers, so here I am.

In: 0

Either smoke produced by the larger fires cause it to get darker or in your case, your eyes adjusted to the brightness of the candle, causing the outside edges to appear darker. I’m sure the moment you looked away from the candle it appeared normal/brighter.

Go find a mirror and take a look at your eyes.

You will notice there is a black circle in the middle surrounded by a colored, seemingly textured band, surrounded by white of the eyeball. The black circle is an actual opening that lets light into the eye (the pupil), while the colored band is a ring of muscle (the iris) that can open and close to change the size of the pupil.

When you look at something bright such as a fire the iris will close to reduce the amount of light coming into the eye. This means that when you look back at the area surrounding the fire your iris is more closed and less light is allowed in, making it seem darker. When you are in a dark area the iris relaxes and opens up to allow more light in so things seem brighter.