Tears of birds/reptiles same as Human tears


Are tears of birds and reptiles same as that of human beings? A new study has found that the composition of tears of birds and reptiles are same as that of human beings. Though the composition is the same, there is structural difference when the tears form crystallised substances.

Frontiers in Veterinary Science published the report. The researchers said that the only difference in crystallised form was because of “different microelements present in the tears of wild species”.

The researchers said that the findings would help in better eye treatments for humans. These studies would also help in studying tears across different species.

Professor Arianne P Oria (Federal University of Bahia, Salvador, Brazil,) who is first author of the study said that the finding of how tears are able to maintain ocular homeostasis in varying conditions was crucial for understanding the evolution and adaptation processes. It will also lead to new molecules for ophthalmic drugs.

The researchers analysed tears of seven captive species of birds and reptiles. The tears of Macaws, hawks, owls, tortoises, turquoise fronted amazon (a type of parrot), sea turtles and caimans (a type of crocodile) were analysed. The tears of these reptiles and birds contained similar amounts of electrolytes like sodium and chloride. However, the bird and reptile tears had slightly higher concentrations.

The researchers found uniqueness in Sea turtle and caiman tear crystals, mainly because of the adaptation to their aquatic environments.


The study said that thicker crystals in human tears might be mainly because of the increased presence of mucus or macromolecules. Though structural differences are found in tears between human other species, Prof Oria said that some components of this fluid (electrolytes) are present in same concentration in both humans and the species.

The researchers opined that further study was needed to understand more about the role of tears.



Please enter your comment!
Please enter your name here