Can Turtles See in the Dark?
The short answer to the question “Can turtle see in the dark?” is, yes they can. Their vision is similar to humans in that their eyes adjust to the darkness and then they can make out some shapes. But also, like humans, they don’t have night vision like a cat and turtles don’t see clearly in the dark.
How Do Turtles Perceive Colors?
The human eye recognizes red, blue, and green as the main colors. Turtles see these same colors but they see many more variations of red than humans do. This allows turtles to see better than humans do.
Birds and turtles have a particular gene of CYP2J19 that is the one associated with seeing many more shades of red. Turtles and birds are said to have gotten this gene from a dinosaur over 250 million years ago to enable more shades of red in their sight.
Do Turtles Have Favorite Colors?
It’s been proven that turtles do in fact have favorite colors. They are attracted to red, yellow, and orange the most. When they see any type of object in these three colors, they will most likely go to them to investigate them. It’s suggested that they want to check them out to see if they are edible.
How Do Turtles’ Vision Work in The Dark?
Turtle’s vision works pretty much the same as our human vision in the dark does. When you are in a room with a light and then the lights are turned out, you can’t see anything at that particular moment. But your eyes adjust with the pupil growing larger to take advantage of the little bit of light in the room.
Then, after your eyes adjust for a short while, you can make out shadowy forms in the dark. When a turtle is looking at something in the dark it also has a red hue to it that we as humans don’t see.
Is A Turtle’s Vision Similar to a Dog in the Dark?
Dogs have a retroreflector that is right behind the retina called the tapeturn lucidum. It reflects the visible light to increase the photoreceptors so they can see clearly in the dark. Turtles do not have this retroreflector, so they do not have a clear nighttime vision as a dog does.
When you take a photo of a dog at night in the dark and shine a flashlight at their eyes or direct the flash from the camera to their eyes, you will notice in the picture that the dog’s eyes appear to be glowing in a reddish color.
If you use a similar scenario with your turtle to take a picture at night, your turtle’s eyes will not glow because he doesn’t have a retroreflector.
Do Turtles See Better on the Land or In the Water?
Most all turtles are semi-aquatic or aquatic. Aquatic turtles spend most of their lives living underwater. They will only come out of the water to get a breath of air or to bask on warm rocks or logs. Sea turtles will come out of the water to lay their eggs on the banks or shoreline of a body of water.
It’s essential that turtles be able to see both underwater and on land. Turtle’s eyes are well adapted to seeing in the water and in the air as well.
The Anatomy of Turtle Eyes
Human eyes have a curved cornea to refract light so we can see clearly in the air. But, when we go underwater, the cornea can’t refract light so we don’t see very clearly or very far.
Aquatic creatures, such as fish, rely on their lenses to refract light and they have a cornea, but it’s just there to protect the eyes. Turtles need to see clearly on land in the air and also underwater as well. They have flat corneas and spherical lenses for perfect vision in the air and on land and underwater too.
Turtle eyes have the same number of rods and cones in their eyes, making them work best in bright light. Turtles are diurnal, meaning they sleep mostly at night and stay awake mostly in the daytime as humans normally do.
Sea turtles in the wild are known to see bioluminescence in their prey underwater so that the prey glows and it is easier to find even in very deep water where there is no light.
How Do Turtles See When They are Under the Water?
Humans can see some when they are underwater, but only for a short distance in front of them. Turtles have evolved to see differently as they are mainly water creatures that spend a lot of time underwater in very deep water. Sea turtles in the wild have tears that protect their eyes from the salt in the sea or ocean.
The tears prevent the eyes from getting bacteria in them also and it helps them to see better underwater. The only thing that affects turtles’ sight in the water is if it is cloudy and dirty and then he can’t distinguish items that he sees.
Should I leave a Light on At Night For My Turtle?
Light and darkness affect the sleep patterns of all humans and animals. If you leave a light on for your turtle 24/7, its body won’t know when it is day or night and it won’t rest as well at night as it should. The understanding of it being day or night is necessary for the body to make melatonin, which tells us all to go to sleep.
It’s best to turn the light off at a certain time when you go to bed and then turn it back on in the morning when you wake up. Animals of all types and humans need restful sleep in order to stay healthy and a sleep-deprived turtle would not be happy. If possible, turn the light off and on at the same time each night and day.
In the day, turtles do need some light for them to bask in. It regulates their metabolism and absorbs essential nutrients when they bask. If your turtle doesn’t have the proper lighting in the day that he needs, he can become very distressed and have health issues.
Veggies Are Crucial For Turtles’ Eyesight
All turtles, no matter what type or size, need a lot of Vitamin A in their diet. Turtles don’t store this nutrient in their bodies. If your turtle doesn’t get enough Vitamin A, they will get swollen eyelids, which in turn hinders their vision. Some excellent veggies for your turtle include any yellow, red, or orange vegetables.
Conclusion
It is noted that turtles can see in the dark, but not as clear as they do in the daytime with more available light. Seeing in the dark takes a bit for the turtle’s eyes to adjust to the dark, just as it takes humans a while to see in the dark and distinguish shadowy figures.
