Doesn't sound like allergies, especially because it is one eye, as Wylie's mom pointed out.
Could be hair in the eye, which sometimes can be difficult to detect. Max used to get long hairs wrapped up into his eyelid and I didn't know until I became expert in finding them. He also gets shorter hairs poking into the corner of one eye.
It is also possible for dogs to suffer dry eye in one eye, a lack of adequate tear production. There is a test for tear production, as well as a test to detect scratches and ulcers that cannot be seen without a special dye. Both are easy and inexpensive tests. Special meds are required to prevent further problems.
Could also be conjunctivitis as Taylor suggested, as happened with her pup.
Not all regular vets are great with eyes. I would look for a vet with advanced training in eye care or a specialist. Max had lots of eye problems when he was younger and we were lucky that our vet just happened to have advanced training because he was a pet ER doc.
__________________ Kristin, Max and Teddy  |