SamL

Yes. It happens with linear patterns. It's less noticeable if the lines are thick and pretty much unnoticeable if the image is colorful. The image I posted works really well because the lines are so thin and black. For example, this image doesn't work whatsoever: http://www.lyrois.com/blog/i/lrs-ss08-wp-original-1.jpg But this one works really well to the point where not only the lines are colorful, but the squares fill up with different shades. The cool thing is if I zoom in or out, all the colors suddenly shift: http://3.bp.blogspot.com/-Y5sXRf9d60I/Tb4fiH9qCgI/AAAAAAAAFqM/4OV_Df3uOpU/s1600/graphpaper.gif

I got a mild case of HPPD 5 months ago from the use of muchrooms. After I realized I got HPPD, I didn't use any drugs and I am pretty much cured now. I barely notice anything beside very mild static when I wake up and very weak closed eyed hallucinations if I am tired. A few weeks ago, I noticed that I was seeing colors on graph paper. For example if I look at the image below, the lines turn green and purple and the hexagons fill with a faint shade of orange and blue: http://www.cadcourse.com/winston/Images/TCW90INI/HONEYCOMB.gif Could this be related to HPPD? Has anyone experienced something similar? I worried that if HPPD didn't cause this, it might be a brain tumor or something. I am considering going to my doctor to get an MRI or something but I don't want to make a big deal out if it in case it's nothing to worry about.