Eye conditions in tortoises

Tortoises are thought to have poor eyesight. Their eyelids are quite different to ours; if you look at your own eye you will see that you have a big upper eyelid which comes down to cover your eye when you blink and a much smaller lower eyelid. In tortoises the lower eyelid is the one which is bigger and stronger. Tortoises also have a third eyelid which sweeps across the surface of the eye to clean it when they blink.

The colored circle in the eye is called the iris; this determines whether the eyes are green, blue or brown. The pupil is in the center of the iris; the pupil will be black and round and can become bigger or smaller depending on the amount of light in the environment.

Tortoises have round pupils and they have tiny bones in the white part of their eyes called scleral ossicles. These help to give the eyeball extra strength.

Conjunctivitis is the inflammation of the eyelids, and is often caused by a bacterial infection.

Tortoises that have been in hibernation will sometimes wake up with sore eyes. You can try initially bathing the eyes with lukewarm water on cotton wool before taking him to the veterinary practice to get his eyes checked.  Low temperatures in your tortoise’s house reduces his ability to fight infection. A well balanced diet is vital to keep your tortoise healthy and allow him to hibernate safely.

If your tortoise has conjunctivitis you should take him to the veterinarian who will be able to treat him with antibiotics.

Hypovitaminosis A is caused by a diet lacking in vitamin A which can lead to swelling of the eyelids. Make sure you feed a balanced diet with enough vitamin A to prevent eye problems in your tortoise. However, it is also important not to give too much vitamin A as this can lead to liver damage.

Any trauma to your tortoise’s eye could cause serious damage. This could happen in any number of ways. Examples would be, bedding caught in the eye or a scratch by a sharp object. An ulcer may form on the cornea, which is the transparent outer layer of the eye. Ulcers are very painful and in severe cases the eye could burst. If you see any abnormalities in the eye you must allow your veterinarian to examine your tortoise’s eye.

To prevent eye trauma you should check your tortoise’s house and furniture carefully for any sharp objects. Remember when handling your tortoise outside of his house care should also be taken. Take care when selecting a UV light for your tortoise’s house. Inferior lights can emit harmful rays which could burn his eyes. If you suspect your tortoise has suffered trauma to his eye seek veterinary attention immediately so appropriate treatment can be prescribed.

Eye damage is an emergency and if not treated in time your tortoise may lose his eye.

Yes, they do!

A cataract is when a change occurs within the lens of the eye. Normally the lens is perfectly clear to allow light to hit the back of the eye (the retina). A cataract causes the lens to become hard and cloudy preventing light reaching the back of the eye. Some tortoises develop cataracts after hibernation.

Cataracts do not cause pain. However, the eyesight will be affected and you may notice your tortoise bumping into things. You may need to assist in feeding your tortoise if he struggles to see. Cataracts are very difficult to remove because the tortoise eye is very small.