Have Reptile Veterinary Questions? Ask a Reptile Expert.
My name is ***** ***** I have been a Vet tech for 30+ years with special interest in reptiles and reptile rescue.
You can use some Plain Saline Eye drops without preservatives. As far as the Gentamycin, it is commonly used for eye infections, but it is a prescription medication, so I cannot recommend you that you can use since it would be a legal violation. There is no patient relationship. I can recommend Terramycin ointment which is svery similiar and is OTC medication. It can be gotten on line here: http://www.beautifuldragons.com/Terramycin.html
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Checking in to see how your water Dragon is doing. I hope my information was helpful and the eyes are looking better.