Fri. Feb 23rd, 2024
How to see better in the dark

We all long for the peace and quiet of a moment in the dark, contemplating the beauty of the night sky. But sometimes it’s hard to make out things in the pure darkness of provincial parks.

Did you know that you can actually improve your ability to see in the dark? Most people don’t realize that there are several techniques they can use to improve their night vision. In this article we will explain four things you can do to see better in the dark.

We hope it allows you to not only see more objects in the night sky, but also safely navigate your campsite at night.

Understanding the eye

Before we get into any of our specific techniques, let’s talk a little about the eye.

The eye is one of the most amazing structures found in the animal kingdom. It is often considered an extension of the brain itself. So, the next time you look into someone’s eyes, you’ll actually be looking at their brain!

eye diagram

The white part of the eye provides protection and support to the retina, which is located at the back of the eye. The most visible part of the eye is the iris, the green part in the diagram above. The pupil is the part of the eye through which light passes, represented by the black circles in the diagrams.

Our eyes have evolved to give us the ability to see reasonably well both day and night. In sunlight, our pupil constricts to a very small opening to protect our visual receptors from excess light. At night, our pupil dilates to let in as much as possible.

Light travels through the pupil of the eye and focuses on the back of the retina. The retina is made up of billions of photoreceptor cells, which help us see color, sharpness, and dark objects. When light hits a photoreceptor, a chemical reaction occurs that results in an electrical signal sent to the brain.

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Two uniquely different cells are involved in vision. The “cones” allow us to see color and sharpness, and are concentrated in the center of our vision. They are sensitive to color, but not too sensitive to faint objects. “Rods” allow us to see faint objects, but are relatively insensitive to color. The rods are more concentrated in a ring around our central vision.

eye diagram

When seeing faint objects, we must rely more on our rod photoreceptors than our cones. As a result, we should do everything possible to improve the light sensitivity of the rod.

How the eye adapts to the dark

night sky in winter

In the dark, our eyes go through a process of replenishing their chemical photoreceptors, which are in constant use when seeing. The process of replenishing the chemicals in our photoreceptors is known as dark adaptation and lasts 20 to 30 minutes on average.

That’s why you easily find your way to the refrigerator for a midnight snack, but if you turn on a bright light, you have a harder time finding your way back.

The four techniques that can be easily used to improve your night vision are:

  • Protecting your eyes from extreme conditions
  • Keep one eye closed before observing.
  • Using a red filter
  • Using deviant vision

Protecting your eyes from extreme conditions

winter cycling

The first tip should seem obvious now, and that is to keep as much light as possible before it gets dark.

The more chemicals the photoreceptors use to respond to light conditions, the longer it takes to adapt to darkness. Evidence suggests that if one has been exposed to very bright conditions, it could take hours to adapt to the darkness. This includes a bright sun on a snowy background or a bright sandy beach. Caution should be taken when wearing sunglasses during the day to protect the quality of night vision.

Keep one eye closed before observing.

Illuminated tent and stars.

The second tip is to keep one eye closed before exposing yourself to bright light. Say, for example, you need to grab something from your backpack at night and you have to turn on a flashlight to find it. Keep one eye completely closed and use the other to find that item in the backpack with the flashlight on.

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Now, after turning off the flashlight, open the closed eye and close the open one. You will be able to see much better in the dark with your eye previously closed and not exposed to light. Until you become dark adapted, you won’t be able to see much with your eye exposed to the flashlight. This may seem very silly, but we promise it works great!

Using a red filter

night sky

Is there a way to use our knowledge about rod and cone receptors to protect our night vision? Actually, the answer is yes!

Since we only use our sticks for night vision, there is a trick we can use. It involves using a color of light to which the rods are practically insensitive and the cones see well: red light. It turns out that using only red light at night is an extremely effective way to preserve night vision. Cover your flashlight with a red filter or wear red glasses in places where you can’t.

Using deviant vision

night sky

The last of our tips is to maximize the use of our rods by knowing how to look at something that is weak. Let’s take a look at our cones and rods again.

eye diagram

You can see that while the cones are focused toward your central vision, the rods are not. They are concentrated in a ring that is about 20 degrees from central vision. So, to maximize your sticks, you can aim your gaze so that the object you want to see is about 20 degrees off center.

Galaxy photograph taken by the Hubble telescope

An example is looking at the Andromeda galaxy. If one goes to the dark skies of our provincial parks, one can see the Andromeda galaxy in the Andromeda constellation. However, trying to see this faint patch of light by staring at it is somewhat challenging.

On the other hand, if you look away to look at a star 20 degrees from the center, the galaxy will “pop” into view within your peripheral vision. This amazing trick is known as using averted vision.

We hope that by using a combination of these four techniques, your enjoyment of camping and night viewing will be greatly increased!