Sounds like your dog may have something stuck in its eye. You might try holding the eye open and flushing with water. I would recommend getting it into the vet to have it checked out to make sure there is not severe damage to the eye. For now try to keep it as clean as possible with a warm cloth.
Another piece of unrelated advice for getting rid of foul smell under the eye(where the tear stains usually are) apply small amount of destin to this area, this keeps moisture out. BE SURE NOT TO GET DESTIN IN THE EYE.
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