This technology slightly intensifies the dark image so you can see it better, and in greater detail. The more traditional “green” night vision requires at least a small amount of light, similar to your own eyes. Once the camera converts these infrared images, you’re able to see objects that appear to be glowing. Since your eyes can’t see infrared radiation, images or videos captured by thermal cameras have to be processed. They’re commonly used for seeing people or animals at night, since visible heat from the body creates a stark contrast to a cooler, darker background. Thermal cameras can function in total darkness, but only in the presence of objects that contain or emit heat. Anything you feel as heat usually qualifies as infrared radiation. Thermal (infrared) cameras focus on radiation just past the visible scale. The visible light you see makes up only a tiny portion of the electromagnetic spectrum, a scale that includes every type of radiation. You would perceive this absence of light as complete blackness. Without a light source, all forms of shape and motion will disappear, rendering your eyes useless. Walk far enough into an underground cavern, and you can experience true, absolute darkness for yourself. There’s always light creeping in from the moon, stars, streetlight or alarm clock.Įven the smallest amount of light can give your eyes enough to work with. Your night vision works outdoors and in your home because it’s almost never completely dark. Your eyes’ rod cells may be hypersensitive, but they aren’t so sensitive that they can make something out of nothing. If you’ve ever experienced a darkness so sweeping that you can’t see your hand in front of your face, you’ll know the answer is no. SEE RELATED: 11 questions answered about how animals’ eyes work This feature is called a tapetum lucidum, and it gives their eyes that colorful, reflective glare at night. Cats and dogs, along with cows, horses and deer, have an iridescent coating behind the retina that boosts their scotopic vision. What they lack in night vision they make up for in vibrant colors and contrast during the day.Īnimals that are nocturnal or spend more time in the dark tend to have better night vision. It takes your eyes 5 to 8 minutes to start adjusting to darkness, but they don’t reach maximum adjustment until you’ve been in the dark for about 40 minutes.īut there’s a good reason for all of this: Humans are primarily daytime beings. In fact, reaching your maximum level of night vision is almost painfully slow. At least compared to the rest of the animal kingdom.Īnd adjusting to the darkness certainly isn’t a quick process for a human either. Unfortunately, one of the downsides to being a human is that the night vision isn’t great. Last time you got up in the middle of the night, were you frustrated by just how little you could actually see? Not very vibrant, is it? Do humans have good night vision? Look around next time you’re lying in a darkened bedroom. This is why your night vision usually isn’t very colorful and often seems to be in black and white. Without rods scattered across your retinas, any sort of darkness would be virtually blinding.īut there’s a catch: Rods can’t process color.

Rods excel in peripheral vision and are much more sensitive to light photons, which makes them extremely helpful in low-light settings.

While cones are great at registering bright lights, colors and fine details, they’re not so useful for helping you see in the dark - that’s where your rods come in. When the right light strikes them, they send tiny impulses along your optic nerve and into the back of your brain. Rods and cones each react a little differently to varying types of light. These rods and cones are necessary for eyesight. There are millions of rod-shaped and cone-shaped cells along every eye’s retina.

For that, you have to look at the microscopic cells in the back of your eyes. This automatic process is one reason you have scotopic vision, but it doesn’t show the entire picture. If you’re fast enough, you’ll see your pupils quickly shrinking. To witness this firsthand, stand in front of a mirror in a darkened room, then ask someone to turn on the lights. In a brighter setting your pupils shrink back down, since they have all the light they need to see comfortably. They do this by opening the pupils wide and allowing your eyes to catch as many rough outlines and shapes as they can. In a dark setting, your eyes like to gather as much light as possible. It can come in pretty handy when you need it. It kicks in when different components, in particular your pupils and retinas, work together inside your eyes. Night vision, also called scotopic vision, is your natural ability to see in the dark.

Night call hat