So, the whole world looks like a stained glass window with only shades of blue? I've seen that. Mostly when I took sildenafil and my blood pressure meds at the same time.
Here's a write up that explains some of the visual side effects of PDE5i drugs. According to the writeup none of the side effects involve long-term harm.Pathophysiology of visual disorders induced by phosphodiesterase inhibitors in the treatment of erectile dysfunction
(May be a bit sciency for some of you. It sure was for me.)