Van Gogh's Digitalis problems

So we learned about Digitalis last week at school, it is a drug that is used to treat heart failure. Well if you take too much of it and experience some toxicity problems, your vision starts to turn yellow and greenish, and you start to see lights being more blurry than before. Also, one source of the drug is the foxglove plant. So after explaining all of that the professor lecturing us explained that there was an article released in JAMA, a medical journal, in which someone explained that Van Gogh, prior to 1888, had mostly painted with lots of browns and blacks, with kind of a depressed, somber tone. After 1888, we start to see an drastic change in the coloring, with an increase in yellows and greens. And he even painted a picture with his doctor in it, with the foxglove in the corner. So, one idea is that after 1888 his doctor started to treat him with foxglove, which was used for a variety of medicinal purposes at the time. Van Gogh is thought to have been overdosing (or suffering some other form of toxic reaction) on foxglove, or Digitalis, and had thus been suffering the effects of yellow vision (seen in his paintings) and then the blurry lights, as seen with the blurry stars in the starry night painting. Kinda cool huh? A medical explanation for one of the world's great artists. Here is the picture with his doctor and the foxglove flower seen in the bottom of the painting.

Starry Night (note the blurred stars)

Some of his yellow-er paintings

There are more, but I don't want to look them up.