I woke up with a blurry spot in my left eye. no other symptoms like numbness, pain, filmy eyeetc. i may have a sinus infection. should i be concerned?

Blurred vision: Blurred vision can be due to any number of things. If you woke up with blurry vision, it's possible your eye was open during the night and it is now dry, causing blurry vision, especially if you normally sleep on the same side. If the blurry spot enlarges, becomes more dense, or generally is not improving within 24 hours and no associated symptoms, should have eye doctor look soon.

Floaters: It sounds as if you have had a posterior vitreous detachment. This is a situation where the vitreous(jelly) of the eye detaches (not a retinal detachment), it then "crumples" up leaving dots, spots, strands of blurry vitreous; i.e. The "floater". You should have an exam to ensure the incident did not tear the retina, which could lead to a retinal detachment. Wait one year then consider surgery.