LED flashlights and Night vision

Apr 26th, 2012 | Posted by | Filed under LED Light

The best way to view the world at night is with bright, clear, white light, right? Whether maneuvering around a campground, looking for a lost pet, lighting one’s path for trick-or-treating, or for any other activity that requires light at night, using with white lights seems to be the logical lighting solution.

So why is it then that many fishermen, hunters, and military personnel prefer NOT to use white LED flashlights light while navigating at night? Well, in reality, that white light isn’t really helping our vision, it’s destroying our natural night vision. Understanding the mechanics and biological processes behind human vision will help explain why the use of LED flashlights with white light is sometimes avoided at night.

The Workings of the Human Eye

The way a human eye works can be compared to how a camera operates. Both control the amount of light that enters so that there is a clear exposure for the incoming image. The camera records this image on film, but the eye has a slightly more complex system.

Light journeys through the cornea, pupil, the lens, and the jelly-like vitreous humor tissue until it reaches the retina. The retina is a layer of tissue located at the back of the eyeball and is made up of millions of light-sensitive cells called rods and cones. Cones will pick up on color and detail mostly in the daytime. Rods will focus on monochromatic vision in more low-light conditions.

Upon coming in contact with light, the rods and cones send electrical signals to the brain via the optic nerve. Once the brain has translated these light signals, we are able to view the world (our equivalent of the image being recorded on film).

Night vision is produced by chemicals in the rods called rhodopsin. Rhodopsin, a biological pigment that is highly sensitive to light, molecules change shape when they absorb light and this process results in the detection of light.

Ever wonder why it takes time for your eyes to become accustomed to the dark again after being exposed to bright light, such as from an LED flashlight? Well, this happens because those rhodopsin molecules take time (usually around half an hour) to retain their night vision shape after the eye is exposed to bright light.

The light spectrum where rods and cones are more sensitive is also another interesting component of the inner-workings of the human eyeball. On one side, the yellow-green section of the light spectrum, cones are more sensitive, hence why newer crosswalk signs are a bright yellow-green color so that they can stand out to drivers. On the other side, the blue-green section of the light spectrum, rods are more sensitive. So, colors such as red are harder for rods to pick up on. Hence why many outdoorsmen prefer using colored LED flashlights instead of white in order to preserve and protect their night vision.

Now that you just possess a much better idea concerning what some from the inner-workings from the human being eyesight are, it’s time to select probably the most effective LED flashlight for the evening eyesight needs. although most individuals choose LED flashlights that mimic daylight on account of getting additional relaxing within morning time (and our cones can choose up on each coloring and detail), it’s time to think about what flashlight is most appropriate for the evening vision.

There are LED flashlights which could emit yellow-green, blue-green, or red-colored light, as well as a sort of LED flashlight which could consist of all three of all those gentle options, as well as light light.

It may maybe be challenging to select which coloring range to possess collectively with your LED flashlight, so think concerning the utilization of the flashlight.

-Red gentle is exceptional for if you need to create utilization of as small gentle as feasible (rods cannot detect this kind of gentle which would allow it to be exceptional for preserving your evening vision).

-An LED flashlight emitting yellow-green gentle is exceptional for when your phone call for to look at a coloring map (cones might possess the ability to detect the colours and particulars additional easily). should you are worried about defending your evening vision, include one of astigmatism while utilizing the yellow-green light.

-Blue-green gentle is exceptional for utilizing as small gentle as feasible and detail is not required to see.

Now that you just know merely a tiny additional about how the human being eyesight and evening eyesight work, maybe you will choose an LED flashlight that consists of various additional options than just light light.