doesnt have to be an ophthalmologist. you could go to an optometrist.
most likely scenario is refractive error, but the much rarer "bad stuff" like glaucoma, tumor, etc cant be ruled out until you get an eye exam.
Forgot to mention the sinus problem is an allergic one and seasonal. I don't have it now.
I have been to an optometrist last thursday for a contact lens check-up and everything was fine... so not to worry right?