Flashlights with red light: what do you use them for?

More and more flashlights are enhanced with a red LED light. But what do you use this light for? To answer that properly we need to know more about our eyes first. After that everything will be clear.

The light-sensitive part of our eyes is constructed of cones and rods. If light falls on the cones and rods, this information is passed on to the brain. But cones and rods differ in terms of light sensitivity. Cones, in comparison to rods, need a lot of light to be activated.

When it is dark out (and less light falls on the retina) the effect of the cones rapidly decreases. You notice this as it becomes more difficult to read a book. We solve this by turning on the light. There is, however, a downside to this solution: if you are sitting in a well-lit room, you won’t see anything when you are looking into a darker room. This is a nasty side-effect when you are stuck in the middle of the forest and have no idea if you are surrounded by wild animals and cannot read your map.

Fortunately our rods have one quality to make sure we can light up our surroundings and at the same time are able to see in dark surroundings. Rods are namely insensitive to light with ‘longer wavelengths’, namely red light. This is reflected in the fact that red objects look very black at night.

By lighting up your surroundings with red light you supply the cones with enough light to distinguish details. Red light disturbs your night vision less than white light. In addition, red light is pleasant to the eyes, enables you to focus faster, and makes sure that you won’t be bothered by night blindness as much. As a result you can read your map and keep a close eye on your surroundings. That is why many flashlights for hunting purposes and military flashlights are enhanced with a red LED light.

Curious to learn more about all flashlights with red light? We will give you a practical overview.