I have a left eye which is tearing. Blocked duct ruled out. Other symptoms are irritated eyes and sinus symptoms - occasional sneezing.?

Allergic conjunctivi. Sounds like allergic conjunctivitis if an obstructed nld has been ruled out.
Tearing. One possibility is that you are sensitive to your bedding - especially it you sleep more on your left side. Fabric softeners, dust mites, molds or retained detergents can irritate your eyes. You should check with an ENT doc to check your nose and sinuses. The tear ducts empty into the nose.