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What Issues Can Turtle Eyes Have And What Can They See?

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Turtles are very popular with both adults and children as they are beautiful, interesting, and very striking to watch. They are extremely skilled in their natural habitats as they can quickly catch prey, but what exactly can turtles see?

Turtle eyes are the part of a turtle that we do not know a lot about. What colors do turtles see? How far away can they see? Are they able to see in the dark? A lot of these questions are unanswered, even to those who take a keen interest in turtles.

Turtle eating vegetables

So how can we find out more about turtle eyes and what they see? 

This article will inform you about turtle eyes and any issues that they can have with them. It is important to sort out any eye issues when you first notice them, so find out how to spot them here!

Are Turtles Able To See Color?

After much research, it has been proven that turtles can see color. They react to different colors in different ways, but the research has shown that the colors that turtles can see are on a wider spectrum than the colors that humans can see. 

The Color Red

Research that has been published in the Proceedings of the Royal Society B shows that reptiles can see the color red differently than humans. As turtles are reptiles, they see red differently, but how?

A gene called CYP2J19 allows turtles to see more shades of the color red than humans. As they can see more shades, they are also able to tell the difference between shades that look incredibly similar in color, which humans are unable to do.

Similar colors, such as scarlet and crimson, can be differentiated by turtle eyes but not by humans. 

The Colors Orange And Yellow

People who have spent a lot of time with turtles, such as volunteers or keepers, have noticed that turtles are attracted to orange, yellow, and red. Some studies have shown that turtles who take a particular interest in these colors are trying to see if they can eat the object. 

If you see a turtle investigating orange, yellow, or red objects, they are more than likely trying to find out if it is edible. 

How Are Turtles Able To See Underwater?

Human vision underwater is blurry due to our corneas. Naturally, our corneas are curved, which means that they refract light, so we can see clearly above water. The curve in the corneas means that we cannot see underwater as they cannot refract the light.

To ensure that they can see both underwater and above water, turtles have flat corneas. The flat corneas allow them to see clearly, as well as the spherical lenses, meaning that their vision isn’t affected by the water or the air.

Some studies think that turtles can bioluminescent their prey to catch them. 

The rods and cones in turtles’ eyes are distributed evenly to make sure that they are still able to see in bright light. Due to this, turtles can see clearly in the daylight, especially in the tropical countries that they are native to where it is mostly bright and sunny. 

Do Turtles Need To See Underwater?

As turtles are semi-aquatic, they need to be able to see underwater to survive. Their prey lives underwater, so they need to see clearly to be able to catch their food. Usually, you will only see turtles on land to breathe, lay eggs, and lie in the sun.

They need to be able to come up for air, so seeing clearly both in the water and above the water is critical for their survival. 

Are Turtles Able To See In The Dark?

Turtles have a similar vision in the dark to humans. Their pupils shrink and their irises become narrower, so this limits the amount of light that is let into our eyes. The reason that eyes do this is to stop too much light from damaging our eyes, and it is the same with turtles.

However, turtles’ pupils become larger when it is dark to allow them to see. 

Once their pupils become larger in the dark, turtles need some time to adjust to the change of light. After their eyes have adjusted to the darkness, turtles can see quite well in the dark, but not as well as other animals.

Other nocturnal animals have tapetum lucidum, a tissue layer that reflects light to the retina so animals can see in the dark. 

Nocturnal animals like cats and owls have tapetum lucidum, allowing them to see clearly in the dark. Like humans, turtles do not have tapetum lucidum, so although they can see in the dark, it isn’t as clear as other animals.

However, the tapetum lucidum causes nocturnal animals to be 44% more sensitive to light, which wouldn’t be ideal for turtles who need to come above water in the sun. 

Can Turtles See Far?

Underwater, turtles can see long distances due to their spherical lenses and flat corneas. Turtles must have good vision underwater, especially long-distance vision, as they need to spot their prey to catch it.

As they can see well underwater with their flat corneas and spherical lenses, this means that they can only see short distances above water. 

As it is important for turtles to see underwater so they can find their prey, it isn’t as important that they need to be able to see long distances above water. Out of the water, turtles bask on the rocks and breathe, so they do not need to be able to see long distances. 

Can Turtles Have Eye Problems? 

It is important to recognize any eye problems that turtles may be suffering from as they will need treatment straight away.

If eye problems are left untreated, it could permanently affect the turtles’ vision and cause them to struggle to survive both underwater and out of water. 

The main eye problems that turtles suffer from with their eyes are swelling and infections. Eye infections need to be treated immediately as untreated eye infections can cause respiratory tract infections in the turtles as eye bacteria can spread to the nose.

If a turtle has an untreated respiratory tract infection, it could be fatal. 

Swollen eyes can cause the turtle to have difficulty seeing both underwater and out of water. This can make it very hard for them to survive as they won’t be able to find their prey, which could lead to starvation. 

Find out more about these conditions below to make sure that you can spot the signs of eye infections and eye swelling in turtles. 

Swelling Of Their Eyes

Swelling can usually be a sign of an eye infection, but it can also indicate that a turtle is suffering from a vitamin A deficiency. The Harderian glands in the turtles’ eyes become swollen, causing the eyes to appear swollen and puffy.

If you are unsure if a turtle is suffering from an infection or vitamin A deficiency, swollen eyes always need to be treated, so seek help immediately. 

If swollen eyes are not treated properly, the turtle will be unable to open its eyes due to the swelling around the eyes. The longer that this is left, the more chance that the turtle has of becoming blind.

As you will want to avoid the turtle becoming blind, you will need to get the eyes treated quickly. 

What Are The Symptoms Of Swollen Eyes?

Although swelling is the main symptom of swollen eyes, some symptoms can indicate that there is something wrong with the turtle. Looking out for these symptoms can help you to prevent them from having to endure swollen eyes. 

If the eyes are looking puffier than normal or if there is redness around the eye, these are signs that you need to contact a veterinarian.

There are also symptoms such as weight loss and difficulty breathing that can indicate that there is a problem with your turtle that needs to be treated. Any abnormal behavior should always be looked at by a veterinarian. 

How Are Swollen Eyes Caused? 

If your turtle is experiencing swelling of the eyes, it is often a sign of a vitamin A deficiency.

The cause of vitamin A deficiency is the turtle not being fed the right foods, so you must feed them a balanced diet that ensures that they are receiving all of the vitamins and minerals that they need to survive. 

Even if you suspect that vitamin A deficiency is the cause of swollen eyes, it is still important to have a veterinarian look at the swelling. This will make sure that the turtle receives the right help and care to treat its eyes. 

How Can Swollen Eyes Be Treated?

When you are seeking help for your turtle, you will need to get help from a Herp vet. Herp vets specialize in treating reptiles, so they will be able to help your turtle’s swollen eyes.

Drops of vitamin A are often prescribed to help heal the eyes and vitamin A injections will help to improve their vitamin A levels. 

The owner will also be told how to improve the turtle’s diet to ensure they get enough vitamins and minerals to stay healthy. If the swelling is due to an infection, additional treatment will be needed to clear up the infection.

How Can You Prevent Swollen Eyes?

The main way that you can prevent a turtle from suffering from swollen eyes is to make sure that they are being fed the right diet.

A diet consisting of turtle feed and greed foods such as spinach, kale, parsley, lettuce, zucchini, and dandelion leaves can help turtles to get all the vitamins and minerals that they need. 

Eye Infections 

Turtle on grass

As eye infections can lead to respiratory tract infections, they must be treated quickly. As the bacteria can easily go down the nasal passage, this can lead to fatalities.

It is important to make sure that you are aware of the signs of infections in the eyes so they can be treated quickly and properly. 

What Are The Symptoms Of Eye Infections?

If your turtle is suffering from an eye infection, there are several symptoms that you need to look out for. If your turtle is suffering from any of these symptoms, then you need to seek veterinary help immediately.

Puffy eyes or discharge from the eyes can indicate that there is an infection, as well as your turtle rubbing or scratching its eyes. 

The symptoms of a respiratory tract infection are different from an eye infection. The symptoms include difficulty keeping balance when swimming, difficulty breathing, mouth and nose discharge, and sneezing.

If your turtle is experiencing any of these symptoms, you will need to make sure that you seek veterinary attention immediately.

How Are Eye Infections Caused?

There are many ways that eye infections can be caused, especially if turtles are kept as pets.

If your turtles are living in dirty water or poor temperatures, this can lead to eye infections being caused. A vitamin A deficiency is also a cause of eye infections, so it is important to make sure that you keep your turtle’s living conditions and health to a high standard.  

How Are Eye Infections Treated?

Antibiotics are required to treat eye infections, so you will need to seek the help of a Herp vet. You shouldn’t try to treat the infection yourself as this could cause the infection to worsen, so you must seek veterinary attention for your turtle.

If the turtles are kept as pets, the owner will need to improve the living conditions to prevent any further infections.

How To Prevent Eye Infections

The best way to prevent eye infections in turtles is to keep the water clean to reduce the number of harmful bacteria. If the turtles are kept as pets, you will need to clean their aquarium every week and test the water for ammonia and nitrate levels.

If the levels are higher than the recommended level, the water isn’t safe for the turtles to live in. 

Frequently Asked Questions

Are Eye Infections Common?

Eye infections are not that common in turtles as it all depends on the conditions that they are living in. If the water is dirty and full of bacteria, the turtle will more than likely develop an eye infection that will require immediate treatment.

Delayed treatment may lead to permanent eye damage or a respiratory tract infection, so you must look after the turtle and provide it with the right care and water. 

How Do You Make Sure That Turtles Get The Right Vitamins?

A combination of green foods like spinach and kale with feed designed for turtles will provide them with all of the vitamins that they need to stay healthy.

You can also enquire to a veterinarian about supplements for your turtle if they have a deficiency, but your veterinarian will be able to prescribe the supplements needed for your turtle if necessary. 


To conclude, it is important to understand turtles’ eyes and vision to make sure that they are taken care of properly.

Making sure that their vision is healthy and clear is important for their survival, so if you see a turtle suffering from swollen eyes or eye infections, you will need to seek help immediately. 

Understanding turtle eyes is important for understanding how turtles live and survive. It is important to make sure that we care for turtles in both the wild and as pets as we need to make sure that they live to a high standard and are always kept healthy and out of danger. 

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About the author


Kerry White is an avid dog lover and writer, knowing all there is to know about our furry friends. Kerry has been writing for PetDT for three years now, wanting to use her knowledge for good and share everything she can with new dog owners.Kerry has two dogs herself - a German shepherd called Banjo and a chocolate labrador called Buttons. Kerry knows more than anyone how adjusting to new life with a puppy can turn your life upside down, and she wants to ease some of the burdens through her articles.