Do Bearded Dragons Have A Third Eye?
While lurking through Bearded Dragon groups online, I came across a pretty amazing fact. Bearded dragons have a third eye! I just had to look into this mysterious third eye and see what it’s all about. Once I learned more about it, I decided to feature the bearded dragon’s third eye in a post.
Bearded dragons have a third eye called a Parietal, Solar, or Pineal Eye. This photosensory organ is a grey dot on the top of their head, between their eyes, that:
So, now that you know that this eye exists, let’s get into what else it can do and how it’s presence affects how you should handle your pet bearded dragon.
What is the Third Eye (Parietal Eye)?
The third eye can detect light and shadows, including ultraviolet light, and mainly uses this information to warn about threats, direct hormone production, and regulate a bearded dragons internal body temperatures.
Due to it’s ability to sense light and shadow, a bearded dragon’s third eye can also help a bearded dragon determine if it’s day or night, or even what season it is based on the length of daylight.
The third eye communicates with the pineal gland instead of the optic center of the brain, so it doesn’t see objects in the same way that the other two eyes do. The retina and lens on this third eye aren’t as developed as on a bearded dragon’s two other eyes, and it uses a different biochemical method than them to detect light. Also, the parietal eye doesn’t have an eyelid.
The Third Eye Helps Bearded Dragons Navigate
In addition to this, studies have shown that the third eye can help a bearded dragon navigate based on the position of the sun.
Parietal eye testing was performed on Italian wall lizards at Italy’s University of Ferrara. Researchers surrounded a pool with fencing and trained the lizards to swim across the pool onto a small ledge. There was nothing blocking the sky, so the lizards could use the sun as a point of reference.
Once the lizards were able to successfully swim across the pool, scientists moved them into closed rooms for a week so that they could control the light cycle. Some rooms had lighting that matched the natural day and night cycle going on outside. The other rooms used erratic lighting to throw off the lizard’s internal clocks.
The researchers performed swimming tests on the lizards again and only the lizards that were in the first rooms were able to successfully swim to the ledge. The other lizards appeared to be confused by the differences in where their internal clocks expected the sun to be and where it actually was.
This result was further confirmed when scientists covered the parietal eyes of the lizards and ran the swim test again. The lizards appeared to lose their sense of direction and ended up swimming randomly around the pool.
How To Make Sure Not To Startle Your Bearded Dragon
Now that we’ve gone over what the third eye is and how it helps your bearded dragon analyze the world around it, let’s get into how this knowledge should affect the manner in which you handle your dragon.
In nature, the parietal eye helps your bearded dragon to avoid predators that are swooping in from above. They sense where the predator is blocking sunlight and immediately go into high alert mode and try to escape.
A captive dragon will react the same way to a hand that is blocking the light above their parietal eye. That’s why it’s important to always approach your dragon at it’s eye level. It’s easier to do this if you have an enclosure with front or side doors.
When picking up your bearded dragon, always make sure to reach beneath it’s belly and that all of your dragon’s legs are supported by your hand or hands. Please note that you also want to make sure that the dragon has adequate support beneath it’s tail.
Lift the bearded dragon slowly and make sure that nothing is approaching it at a fast speed which would stress it out. Don’t lean over the it, as this will block the light to it’s parietal eye.
Make sure block the area in front of the bearded dragon’s face so that it is less likely to try to run away and fall out of your hands. Also, stay alert because they don’t always have a good sense of the distance to the ground when you pick them up. Bearded dragons have been known to jump out of hands or off of shoulders.
How to Prevent Damaging the Third Eye
The Parietal eye is protected from damage by a clear scale that covers it. As long as you protect your bearded dragon’s head from any trauma or toxic materials, then you shouldn’t have issues with this eye.
To protect all of your bearded dragon’s eyes, be mindful to ensure that your dragon has the proper distance from it’s UVB light/s. This distance is usually somewhere between 6 to 12 inches away from the dragon.
That said, UVB lights that are sold for reptiles should have a chart in the packaging that lets you know what the appropriate ranges are for that specific product. We use the 24″ Zoo Med T5 Reptisun 10.0 for our big enclosure (40+ gallon).
I wouldn’t suggest using a mercury vapor bulb as these can sometimes put out more UVB rays than are healthy for the dragon. You would need an expensive meter to know if the UVB level is too high.
You should also ensure that the heat bulb for the bearded dragon is far enough away that the dragon doesn’t get burned. The hottest section of the bearded dragon’s enclosure, the basking spot, should be a max of 110 F.
Thanks For Reading!
The third eye is a pretty cool feature that is present among different animals. Hopefully, this post made you more feel more confident in understanding your bearded dragon’s biology shows you just how amazing our little beardies are.
Now, I want to hear about the first time that you learned about your bearded dragon’s third eye.
Did it weird you out?
Is the third eye on your bearded dragon pretty obvious?
Do you have any other pets with a third eye?
Leave a comment below to share your experience.
Further Reading & Sources
Lizards Use Third Eye to Steer by the Sun – Wired
Parietal Eye – Wikipedia.org
Survey of the Development and Comparative Morphology of the Pineal Organ – OKSCHE A., Prog Brain Res. 1965;10:3–29.
Influence of the parietal eye on activity in lizards. – Stebbins, R. C., and Daniel C. Wilhoft. In The Galapagos. Proceedings of the Symposia of the Galapagos International Scientific Project. University of California Press, Berkeley (pp. 258-268).
Neural Activity in the Parietal Eye of a Lizard – MILLER WH, WOLBARSHT ML., Science. 1962 Jan 26;135(3500):316–317.