I started taking lisinopril march 12, 2012, I also take Norvasc (amlodipine) for blood pressure. I started seeing floaters, could the lisinopril be causing this?

Unlikely. If your blood pressure drops too much after taking both Lisinopril and norvasc, (amlodipine) it is possible to see 'floaters' as consequence. Check your blood pressure at the time when you see the 'floaters' and if it's not low, look for another cause - see an ophthalmologist.
Not likely. Lisinopril is a good antihypertensive and it is likely that your 'floaters' arrived coincidentally. Floaters are an ocular issue and if you have never been evaluated you need to get in to an eye professional for a thorough eye exam as this issue may indicate a retinal problem.