I would say that you suffer from migraines. Have you had it for a long time and / or have you had a nasty knock to the head recently? When I get the same symptom as you describe in your question, I also notice that I can not read road signs for example, it is like looking at a jigzaw puzzle, all the letters are scrambled and all over the place. As soon as I notice these funny lines in my vision, mostly in the left upper corner of my eye sight, I look for advertising or street signs to see if they are readable or if jigsawed. If I am home, I just look at a picture or t.v and if I see the same effect, I know I am on my way to a migraine. If you close your eyes and can still see those wavy lines aswell, my recomendation to you is, immediately take some asprin, like 2-3 tablets provided you are not allergic to asprin. When ever I get the the same symptoms and I immediately take 2-3 asprin's, I do not suffer the headaches, had I not taken them. See a doctor when you can. I drive for a living and as soon as I get those symptoms, I take my asprin. I end up with no head aches, but my brain/ mind do suffer a bit, yet no pain and can continue working.

Did you ever figure out what this is, because I have been getting the same thing!

I also have this symptom occasionally. A friend said that her father had this as well and it was diagnosed as a "painless migraine." When it happens to me, I take a pain pill (aspirin or tylenol) and the wavy lines go away.

its a migrane